diff --git a/Cargo.lock b/Cargo.lock
index 56385f0214663..3fe7bb2f3f251 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -11437,6 +11437,7 @@ version = "28.0.0"
 dependencies = [
  "frame-support",
  "frame-system",
+ "pallet-balances",
  "pallet-session",
  "parity-scale-codec",
  "scale-info",
@@ -11589,6 +11590,7 @@ dependencies = [
  "frame-support",
  "frame-system",
  "log",
+ "pallet-balances",
  "pallet-beefy",
  "pallet-mmr",
  "pallet-session",
@@ -12431,6 +12433,7 @@ dependencies = [
  "frame-system",
  "log",
  "pallet-authorship",
+ "pallet-balances",
  "pallet-session",
  "parity-scale-codec",
  "scale-info",
@@ -13215,6 +13218,7 @@ dependencies = [
  "frame-system",
  "impl-trait-for-tuples",
  "log",
+ "pallet-balances",
  "pallet-timestamp",
  "parity-scale-codec",
  "scale-info",
diff --git a/cumulus/pallets/collator-selection/src/benchmarking.rs b/cumulus/pallets/collator-selection/src/benchmarking.rs
index 24823661383b5..706695106ba69 100644
--- a/cumulus/pallets/collator-selection/src/benchmarking.rs
+++ b/cumulus/pallets/collator-selection/src/benchmarking.rs
@@ -49,8 +49,8 @@ fn create_funded_user<T: Config>(
 	balance_factor: u32,
 ) -> T::AccountId {
 	let user = account(string, n, SEED);
-	let balance = T::Currency::minimum_balance() * balance_factor.into();
-	let _ = T::Currency::make_free_balance_be(&user, balance);
+	let balance = <T as pallet::Config>::Currency::minimum_balance() * balance_factor.into();
+	let _ = <T as pallet::Config>::Currency::make_free_balance_be(&user, balance);
 	user
 }
 
@@ -90,7 +90,10 @@ fn register_candidates<T: Config>(count: u32) {
 	assert!(CandidacyBond::<T>::get() > 0u32.into(), "Bond cannot be zero!");
 
 	for who in candidates {
-		T::Currency::make_free_balance_be(&who, CandidacyBond::<T>::get() * 3u32.into());
+		<T as pallet::Config>::Currency::make_free_balance_be(
+			&who,
+			CandidacyBond::<T>::get() * 3u32.into(),
+		);
 		<CollatorSelection<T>>::register_as_candidate(RawOrigin::Signed(who).into()).unwrap();
 	}
 }
@@ -144,7 +147,7 @@ mod benchmarks {
 			T::UpdateOrigin::try_successful_origin().map_err(|_| BenchmarkError::Weightless)?;
 
 		// need to fill up candidates
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
 		DesiredCandidates::<T>::put(c);
 		// get accounts and keys for the `c` candidates
 		let mut candidates = (0..c).map(|cc| validator::<T>(cc)).collect::<Vec<_>>();
@@ -161,13 +164,13 @@ mod benchmarks {
 		// ... and register them.
 		for (who, _) in candidates.iter() {
 			let deposit = CandidacyBond::<T>::get();
-			T::Currency::make_free_balance_be(who, deposit * 1000_u32.into());
+			<T as pallet::Config>::Currency::make_free_balance_be(who, deposit * 1000_u32.into());
 			CandidateList::<T>::try_mutate(|list| {
 				list.try_push(CandidateInfo { who: who.clone(), deposit }).unwrap();
 				Ok::<(), BenchmarkError>(())
 			})
 			.unwrap();
-			T::Currency::reserve(who, deposit)?;
+			<T as pallet::Config>::Currency::reserve(who, deposit)?;
 			LastAuthoredBlock::<T>::insert(
 				who.clone(),
 				frame_system::Pallet::<T>::block_number() + T::KickThreshold::get(),
@@ -226,7 +229,8 @@ mod benchmarks {
 		c: Linear<0, { T::MaxCandidates::get() }>,
 		k: Linear<0, { T::MaxCandidates::get() }>,
 	) -> Result<(), BenchmarkError> {
-		let initial_bond_amount: BalanceOf<T> = T::Currency::minimum_balance() * 2u32.into();
+		let initial_bond_amount: BalanceOf<T> =
+			<T as pallet::Config>::Currency::minimum_balance() * 2u32.into();
 		CandidacyBond::<T>::put(initial_bond_amount);
 		register_validators::<T>(c);
 		register_candidates::<T>(c);
@@ -236,12 +240,12 @@ mod benchmarks {
 		let bond_amount = if k > 0 {
 			CandidateList::<T>::mutate(|candidates| {
 				for info in candidates.iter_mut().skip(kicked as usize) {
-					info.deposit = T::Currency::minimum_balance() * 3u32.into();
+					info.deposit = <T as pallet::Config>::Currency::minimum_balance() * 3u32.into();
 				}
 			});
-			T::Currency::minimum_balance() * 3u32.into()
+			<T as pallet::Config>::Currency::minimum_balance() * 3u32.into()
 		} else {
-			T::Currency::minimum_balance()
+			<T as pallet::Config>::Currency::minimum_balance()
 		};
 
 		#[extrinsic_call]
@@ -255,7 +259,7 @@ mod benchmarks {
 	fn update_bond(
 		c: Linear<{ min_candidates::<T>() + 1 }, { T::MaxCandidates::get() }>,
 	) -> Result<(), BenchmarkError> {
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
 		DesiredCandidates::<T>::put(c);
 
 		register_validators::<T>(c);
@@ -264,8 +268,8 @@ mod benchmarks {
 		let caller = CandidateList::<T>::get()[0].who.clone();
 		v2::whitelist!(caller);
 
-		let bond_amount: BalanceOf<T> =
-			T::Currency::minimum_balance() + T::Currency::minimum_balance();
+		let bond_amount: BalanceOf<T> = <T as pallet::Config>::Currency::minimum_balance() +
+			<T as pallet::Config>::Currency::minimum_balance();
 
 		#[extrinsic_call]
 		_(RawOrigin::Signed(caller.clone()), bond_amount);
@@ -275,7 +279,7 @@ mod benchmarks {
 		);
 		assert!(
 			CandidateList::<T>::get().iter().last().unwrap().deposit ==
-				T::Currency::minimum_balance() * 2u32.into()
+				<T as pallet::Config>::Currency::minimum_balance() * 2u32.into()
 		);
 		Ok(())
 	}
@@ -284,15 +288,15 @@ mod benchmarks {
 	// one.
 	#[benchmark]
 	fn register_as_candidate(c: Linear<1, { T::MaxCandidates::get() - 1 }>) {
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
 		DesiredCandidates::<T>::put(c + 1);
 
 		register_validators::<T>(c);
 		register_candidates::<T>(c);
 
 		let caller: T::AccountId = whitelisted_caller();
-		let bond: BalanceOf<T> = T::Currency::minimum_balance() * 2u32.into();
-		T::Currency::make_free_balance_be(&caller, bond);
+		let bond: BalanceOf<T> = <T as pallet::Config>::Currency::minimum_balance() * 2u32.into();
+		<T as pallet::Config>::Currency::make_free_balance_be(&caller, bond);
 
 		<session::Pallet<T>>::set_keys(
 			RawOrigin::Signed(caller.clone()).into(),
@@ -311,15 +315,15 @@ mod benchmarks {
 
 	#[benchmark]
 	fn take_candidate_slot(c: Linear<{ min_candidates::<T>() + 1 }, { T::MaxCandidates::get() }>) {
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
 		DesiredCandidates::<T>::put(1);
 
 		register_validators::<T>(c);
 		register_candidates::<T>(c);
 
 		let caller: T::AccountId = whitelisted_caller();
-		let bond: BalanceOf<T> = T::Currency::minimum_balance() * 10u32.into();
-		T::Currency::make_free_balance_be(&caller, bond);
+		let bond: BalanceOf<T> = <T as pallet::Config>::Currency::minimum_balance() * 10u32.into();
+		<T as pallet::Config>::Currency::make_free_balance_be(&caller, bond);
 
 		<session::Pallet<T>>::set_keys(
 			RawOrigin::Signed(caller.clone()).into(),
@@ -342,7 +346,7 @@ mod benchmarks {
 	// worse case is the last candidate leaving.
 	#[benchmark]
 	fn leave_intent(c: Linear<{ min_candidates::<T>() + 1 }, { T::MaxCandidates::get() }>) {
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
 		DesiredCandidates::<T>::put(c);
 
 		register_validators::<T>(c);
@@ -360,23 +364,23 @@ mod benchmarks {
 	// worse case is paying a non-existing candidate account.
 	#[benchmark]
 	fn note_author() {
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
-		T::Currency::make_free_balance_be(
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
+		<T as pallet::Config>::Currency::make_free_balance_be(
 			&<CollatorSelection<T>>::account_id(),
-			T::Currency::minimum_balance() * 4u32.into(),
+			<T as pallet::Config>::Currency::minimum_balance() * 4u32.into(),
 		);
 		let author = account("author", 0, SEED);
 		let new_block: BlockNumberFor<T> = 10u32.into();
 
 		frame_system::Pallet::<T>::set_block_number(new_block);
-		assert!(T::Currency::free_balance(&author) == 0u32.into());
+		assert!(<T as pallet::Config>::Currency::free_balance(&author) == 0u32.into());
 
 		#[block]
 		{
 			<CollatorSelection<T> as EventHandler<_, _>>::note_author(author.clone())
 		}
 
-		assert!(T::Currency::free_balance(&author) > 0u32.into());
+		assert!(<T as pallet::Config>::Currency::free_balance(&author) > 0u32.into());
 		assert_eq!(frame_system::Pallet::<T>::block_number(), new_block);
 	}
 
@@ -386,7 +390,7 @@ mod benchmarks {
 		r: Linear<1, { T::MaxCandidates::get() }>,
 		c: Linear<1, { T::MaxCandidates::get() }>,
 	) {
-		CandidacyBond::<T>::put(T::Currency::minimum_balance());
+		CandidacyBond::<T>::put(<T as pallet::Config>::Currency::minimum_balance());
 		DesiredCandidates::<T>::put(c);
 		frame_system::Pallet::<T>::set_block_number(0u32.into());
 
diff --git a/cumulus/pallets/collator-selection/src/mock.rs b/cumulus/pallets/collator-selection/src/mock.rs
index 664ba56459ae9..034ef2189deab 100644
--- a/cumulus/pallets/collator-selection/src/mock.rs
+++ b/cumulus/pallets/collator-selection/src/mock.rs
@@ -140,6 +140,8 @@ impl pallet_session::Config for Test {
 	type Keys = MockSessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 ord_parameter_types! {
diff --git a/cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs b/cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs
index acc6bf63ff454..800607f5512f6 100644
--- a/cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs
+++ b/cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs
@@ -837,6 +837,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs b/cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs
index 6825711df38da..98e1f1518f309 100644
--- a/cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs
+++ b/cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs
@@ -890,6 +890,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs b/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs
index c8b41e1cb40e5..25e0d3f51b925 100644
--- a/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs
+++ b/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/lib.rs
@@ -507,6 +507,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/lib.rs b/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/lib.rs
index 0021a5191f755..2ee35714b3107 100644
--- a/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/lib.rs
+++ b/cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/lib.rs
@@ -493,6 +493,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/collectives/collectives-westend/src/lib.rs b/cumulus/parachains/runtimes/collectives/collectives-westend/src/lib.rs
index 2f3ad0e1ffefe..9bf926a6f4933 100644
--- a/cumulus/parachains/runtimes/collectives/collectives-westend/src/lib.rs
+++ b/cumulus/parachains/runtimes/collectives/collectives-westend/src/lib.rs
@@ -506,6 +506,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/coretime/coretime-rococo/src/lib.rs b/cumulus/parachains/runtimes/coretime/coretime-rococo/src/lib.rs
index 82e9683b6f4b5..3c9c368a5fbdf 100644
--- a/cumulus/parachains/runtimes/coretime/coretime-rococo/src/lib.rs
+++ b/cumulus/parachains/runtimes/coretime/coretime-rococo/src/lib.rs
@@ -406,6 +406,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/coretime/coretime-westend/src/lib.rs b/cumulus/parachains/runtimes/coretime/coretime-westend/src/lib.rs
index 0c102108dfe2a..7b7e80f6cdbb0 100644
--- a/cumulus/parachains/runtimes/coretime/coretime-westend/src/lib.rs
+++ b/cumulus/parachains/runtimes/coretime/coretime-westend/src/lib.rs
@@ -407,6 +407,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/people/people-rococo/src/lib.rs b/cumulus/parachains/runtimes/people/people-rococo/src/lib.rs
index 42b5a0b11dd4e..01f5f61e4c092 100644
--- a/cumulus/parachains/runtimes/people/people-rococo/src/lib.rs
+++ b/cumulus/parachains/runtimes/people/people-rococo/src/lib.rs
@@ -368,6 +368,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/people/people-westend/src/lib.rs b/cumulus/parachains/runtimes/people/people-westend/src/lib.rs
index 14a29430f2799..a2d6e942421f4 100644
--- a/cumulus/parachains/runtimes/people/people-westend/src/lib.rs
+++ b/cumulus/parachains/runtimes/people/people-westend/src/lib.rs
@@ -367,6 +367,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/cumulus/parachains/runtimes/testing/penpal/src/lib.rs b/cumulus/parachains/runtimes/testing/penpal/src/lib.rs
index 6a37590ce7cd2..06c09a196c1ee 100644
--- a/cumulus/parachains/runtimes/testing/penpal/src/lib.rs
+++ b/cumulus/parachains/runtimes/testing/penpal/src/lib.rs
@@ -751,7 +751,6 @@ parameter_types! {
 	pub const Period: u32 = 6 * HOURS;
 	pub const Offset: u32 = 0;
 }
-
 impl pallet_session::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
 	type ValidatorId = <Self as frame_system::Config>::AccountId;
@@ -765,6 +764,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/polkadot/runtime/rococo/src/lib.rs b/polkadot/runtime/rococo/src/lib.rs
index 6f26c3962eebc..58593ff606082 100644
--- a/polkadot/runtime/rococo/src/lib.rs
+++ b/polkadot/runtime/rococo/src/lib.rs
@@ -484,6 +484,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 pub struct FullIdentificationOf;
diff --git a/polkadot/runtime/test-runtime/src/lib.rs b/polkadot/runtime/test-runtime/src/lib.rs
index c3071c48985fc..8392bac8795d8 100644
--- a/polkadot/runtime/test-runtime/src/lib.rs
+++ b/polkadot/runtime/test-runtime/src/lib.rs
@@ -51,7 +51,6 @@ use frame_election_provider_support::{
 use frame_support::{
 	construct_runtime, derive_impl,
 	genesis_builder_helper::{build_state, get_preset},
-	pallet_prelude::Get,
 	parameter_types,
 	traits::{KeyOwnerProofSystem, WithdrawReasons},
 	PalletId,
@@ -79,7 +78,7 @@ use polkadot_runtime_common::{
 use polkadot_runtime_parachains::reward_points::RewardValidatorsWithEraPoints;
 use sp_authority_discovery::AuthorityId as AuthorityDiscoveryId;
 use sp_consensus_beefy::ecdsa_crypto::{AuthorityId as BeefyId, Signature as BeefySignature};
-use sp_core::{ConstBool, ConstU32, ConstUint, OpaqueMetadata};
+use sp_core::{ConstBool, ConstU32, ConstUint, Get, OpaqueMetadata};
 use sp_mmr_primitives as mmr;
 use sp_runtime::{
 	curve::PiecewiseLinear,
@@ -340,6 +339,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = pallet_session::disabling::UpToLimitWithReEnablingDisablingStrategy;
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Runtime {
diff --git a/polkadot/runtime/westend/src/lib.rs b/polkadot/runtime/westend/src/lib.rs
index 810033ffdc27b..9c0db32e9cf30 100644
--- a/polkadot/runtime/westend/src/lib.rs
+++ b/polkadot/runtime/westend/src/lib.rs
@@ -538,6 +538,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = pallet_session::disabling::UpToLimitWithReEnablingDisablingStrategy;
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Runtime {
diff --git a/prdoc/pr_7953.prdoc b/prdoc/pr_7953.prdoc
new file mode 100644
index 0000000000000..305a6659bdf09
--- /dev/null
+++ b/prdoc/pr_7953.prdoc
@@ -0,0 +1,64 @@
+title: Add deposit for setting session keys
+doc:
+- audience: [Runtime Dev, Runtime User]
+  description: |-
+    Setting session keys might put some funds on hold in the future, depending on how runtimes use this feature.
+
+    Requires `pallet_session::Config` to specify:
+    * `type Currency`, assigned to an instance of `pallet_balances`.
+    * `type KeyDeposit`, the amount of deposit. Set to `()` to assert no deposit amount is needed.
+crates:
+- name: pallet-session
+  bump: major
+- name: pallet-collator-selection
+  bump: patch
+- name: penpal-runtime
+  bump: major
+- name: rococo-runtime
+  bump: major
+- name: westend-runtime
+  bump: major
+- name: bridge-hub-westend-runtime
+  bump: major
+- name: asset-hub-westend-runtime
+  bump: major
+- name: bridge-hub-rococo-runtime
+  bump: major
+- name: people-westend-runtime
+  bump: major
+- name: asset-hub-rococo-runtime
+  bump: major
+- name: collectives-westend-runtime
+  bump: major
+- name: coretime-rococo-runtime
+  bump: major
+- name: coretime-westend-runtime
+  bump: major
+- name: people-rococo-runtime
+  bump: major
+- name: pallet-im-online
+  bump: patch
+- name: pallet-staking-async-parachain-runtime
+  bump: major
+- name: pallet-staking-async-rc-runtime
+  bump: major
+- name: pallet-authority-discovery
+  bump: patch
+- name: pallet-babe
+  bump: patch
+- name: pallet-beefy-mmr
+  bump: patch
+- name: pallet-beefy
+  bump: patch
+- name: pallet-grandpa
+  bump: patch
+- name: pallet-offences-benchmarking
+  bump: patch
+- name: pallet-root-offences
+  bump: patch
+- name: pallet-session-benchmarking
+  bump: patch
+- name: pallet-staking
+  bump: patch
+- name: yet-another-parachain-runtime
+  bump: major
diff --git a/substrate/bin/node/runtime/src/lib.rs b/substrate/bin/node/runtime/src/lib.rs
index 3a26fc78df3d4..d19c3159f4e19 100644
--- a/substrate/bin/node/runtime/src/lib.rs
+++ b/substrate/bin/node/runtime/src/lib.rs
@@ -687,8 +687,9 @@ impl pallet_session::Config for Runtime {
 	type SessionHandler = <SessionKeys as OpaqueKeys>::KeyTypeIdProviders;
 	type Keys = SessionKeys;
 	type DisablingStrategy = pallet_session::disabling::UpToLimitWithReEnablingDisablingStrategy;
-
 	type WeightInfo = pallet_session::weights::SubstrateWeight<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Runtime {
diff --git a/substrate/frame/authority-discovery/Cargo.toml b/substrate/frame/authority-discovery/Cargo.toml
index 8b48835d07597..095bcfe9449e7 100644
--- a/substrate/frame/authority-discovery/Cargo.toml
+++ b/substrate/frame/authority-discovery/Cargo.toml
@@ -26,6 +26,7 @@ sp-authority-discovery = { workspace = true }
 sp-runtime = { workspace = true }
 
 [dev-dependencies]
+pallet-balances = { workspace = true }
 sp-core = { workspace = true, default-features = true }
 sp-io = { workspace = true, default-features = true }
 
@@ -35,6 +36,7 @@ std = [
 	"codec/std",
 	"frame-support/std",
 	"frame-system/std",
+	"pallet-balances/std",
 	"pallet-session/std",
 	"scale-info/std",
 	"sp-application-crypto/std",
@@ -46,6 +48,7 @@ std = [
 try-runtime = [
 	"frame-support/try-runtime",
 	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
 	"pallet-session/try-runtime",
 	"sp-runtime/try-runtime",
 ]
diff --git a/substrate/frame/authority-discovery/src/lib.rs b/substrate/frame/authority-discovery/src/lib.rs
index 1914ae4cf9ad2..5d3a0d490544d 100644
--- a/substrate/frame/authority-discovery/src/lib.rs
+++ b/substrate/frame/authority-discovery/src/lib.rs
@@ -189,6 +189,7 @@ mod tests {
 		{
 			System: frame_system,
 			Session: pallet_session,
+			Balances: pallet_balances,
 			AuthorityDiscovery: pallet_authority_discovery,
 		}
 	);
@@ -212,6 +213,8 @@ mod tests {
 		type NextSessionRotation = pallet_session::PeriodicSessions<Period, Offset>;
 		type DisablingStrategy = ();
 		type WeightInfo = ();
+		type Currency = Balances;
+		type KeyDeposit = ();
 	}
 
 	pub type BlockNumber = u64;
@@ -226,6 +229,12 @@ mod tests {
 		type AccountId = AuthorityId;
 		type Lookup = IdentityLookup<Self::AccountId>;
 		type Block = Block;
+		type AccountData = pallet_balances::AccountData<u64>;
+	}
+
+	#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig)]
+	impl pallet_balances::Config for Test {
+		type AccountStore = System;
 	}
 
 	pub struct TestSessionHandler;
diff --git a/substrate/frame/babe/src/mock.rs b/substrate/frame/babe/src/mock.rs
index c620c3eb62fef..961c3bb06c4cf 100644
--- a/substrate/frame/babe/src/mock.rs
+++ b/substrate/frame/babe/src/mock.rs
@@ -102,6 +102,8 @@ impl pallet_session::Config for Test {
 	type Keys = MockSessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Test {
diff --git a/substrate/frame/beefy-mmr/Cargo.toml b/substrate/frame/beefy-mmr/Cargo.toml
index 54343bb9ce51a..6adf5bcd871f5 100644
--- a/substrate/frame/beefy-mmr/Cargo.toml
+++ b/substrate/frame/beefy-mmr/Cargo.toml
@@ -33,6 +33,7 @@ sp-state-machine = { workspace = true }
 
 [dev-dependencies]
 array-bytes = { workspace = true, default-features = true }
+pallet-balances = { workspace = true }
 sp-staking = { workspace = true, default-features = true }
 
 [features]
@@ -45,6 +46,7 @@ std = [
 	"frame-support/std",
 	"frame-system/std",
 	"log/std",
+	"pallet-balances/std",
 	"pallet-beefy/std",
 	"pallet-mmr/std",
 	"pallet-session/std",
@@ -61,6 +63,7 @@ std = [
 try-runtime = [
 	"frame-support/try-runtime",
 	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
 	"pallet-beefy/try-runtime",
 	"pallet-mmr/try-runtime",
 	"pallet-session/try-runtime",
@@ -70,6 +73,7 @@ runtime-benchmarks = [
 	"frame-benchmarking/runtime-benchmarks",
 	"frame-support/runtime-benchmarks",
 	"frame-system/runtime-benchmarks",
+	"pallet-balances/runtime-benchmarks",
 	"pallet-mmr/runtime-benchmarks",
 	"sp-runtime/runtime-benchmarks",
 	"sp-staking/runtime-benchmarks",
diff --git a/substrate/frame/beefy-mmr/src/mock.rs b/substrate/frame/beefy-mmr/src/mock.rs
index aa6905306cd6a..7ef8cc4e90ace 100644
--- a/substrate/frame/beefy-mmr/src/mock.rs
+++ b/substrate/frame/beefy-mmr/src/mock.rs
@@ -52,17 +52,23 @@ construct_runtime!(
 	{
 		System: frame_system,
 		Session: pallet_session,
+		Balances: pallet_balances,
 		Mmr: pallet_mmr,
 		Beefy: pallet_beefy,
 		BeefyMmr: pallet_beefy_mmr,
 	}
 );
-
 #[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
 impl frame_system::Config for Test {
+	type AccountData = pallet_balances::AccountData<u64>;
 	type Block = Block;
 }
 
+#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig)]
+impl pallet_balances::Config for Test {
+	type AccountStore = System;
+}
+
 impl pallet_session::Config for Test {
 	type RuntimeEvent = RuntimeEvent;
 	type ValidatorId = u64;
@@ -74,6 +80,8 @@ impl pallet_session::Config for Test {
 	type Keys = MockSessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 pub type MmrLeaf = sp_consensus_beefy::mmr::MmrLeaf<
diff --git a/substrate/frame/beefy-mmr/src/tests.rs b/substrate/frame/beefy-mmr/src/tests.rs
index fb61dc1879415..dd305f1c4e95b 100644
--- a/substrate/frame/beefy-mmr/src/tests.rs
+++ b/substrate/frame/beefy-mmr/src/tests.rs
@@ -202,6 +202,10 @@ fn should_update_authorities() {
 	});
 }
 
+// If you need to modify the test because you added a new event or something to the block or block
+// header you need to update the test by replacing the expected_mmr_root with the new one
+// you can get the new one by running the test while commenting out the first assert
+// and then copy pasting the new mmr root from the log of the second assert
 #[test]
 fn extract_validation_context_should_work_correctly() {
 	let mut ext = new_test_ext(vec![1, 2]);
@@ -214,8 +218,9 @@ fn extract_validation_context_should_work_correctly() {
 
 		// Check the MMR root log
 		let expected_mmr_root: [u8; 32] = array_bytes::hex_n_into_unchecked(
-			"d4f38bcfa95e1f03a06f7545aa95f24f5e10cc0bbd54cf97fbbff66d5be4769f",
+			"322c6a46ac00d3455c87bd9af42ebafb388f589a1b562f5e39b1d0d71bcbe8e0",
 		);
+
 		assert_eq!(
 			System::digest().logs,
 			vec![beefy_log(ConsensusLog::MmrRoot(H256::from_slice(&expected_mmr_root)))]
diff --git a/substrate/frame/beefy/src/mock.rs b/substrate/frame/beefy/src/mock.rs
index a7d717e0b1b00..85a44254aa528 100644
--- a/substrate/frame/beefy/src/mock.rs
+++ b/substrate/frame/beefy/src/mock.rs
@@ -186,6 +186,8 @@ impl pallet_session::Config for Test {
 	type Keys = MockSessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Test {
diff --git a/substrate/frame/election-provider-multi-phase/test-staking-e2e/src/mock.rs b/substrate/frame/election-provider-multi-phase/test-staking-e2e/src/mock.rs
index 292ade8b3f8c3..84c291d518a2f 100644
--- a/substrate/frame/election-provider-multi-phase/test-staking-e2e/src/mock.rs
+++ b/substrate/frame/election-provider-multi-phase/test-staking-e2e/src/mock.rs
@@ -145,6 +145,8 @@ impl pallet_session::Config for Runtime {
 		SLASHING_DISABLING_FACTOR,
 	>;
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 impl pallet_session::historical::Config for Runtime {
 	type RuntimeEvent = RuntimeEvent;
diff --git a/substrate/frame/grandpa/src/mock.rs b/substrate/frame/grandpa/src/mock.rs
index bf1b05ec11c36..6203f0e952349 100644
--- a/substrate/frame/grandpa/src/mock.rs
+++ b/substrate/frame/grandpa/src/mock.rs
@@ -106,6 +106,8 @@ impl pallet_session::Config for Test {
 	type Keys = TestSessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Test {
diff --git a/substrate/frame/im-online/Cargo.toml b/substrate/frame/im-online/Cargo.toml
index 179c4c3ce3b18..f00260feac914 100644
--- a/substrate/frame/im-online/Cargo.toml
+++ b/substrate/frame/im-online/Cargo.toml
@@ -30,6 +30,7 @@ sp-runtime = { features = ["serde"], workspace = true }
 sp-staking = { features = ["serde"], workspace = true }
 
 [dev-dependencies]
+pallet-balances = { workspace = true }
 pallet-session = { workspace = true, default-features = true }
 
 [features]
@@ -41,6 +42,7 @@ std = [
 	"frame-system/std",
 	"log/std",
 	"pallet-authorship/std",
+	"pallet-balances/std",
 	"pallet-session/std",
 	"scale-info/std",
 	"sp-application-crypto/std",
@@ -53,6 +55,7 @@ runtime-benchmarks = [
 	"frame-benchmarking/runtime-benchmarks",
 	"frame-support/runtime-benchmarks",
 	"frame-system/runtime-benchmarks",
+	"pallet-balances/runtime-benchmarks",
 	"sp-runtime/runtime-benchmarks",
 	"sp-staking/runtime-benchmarks",
 ]
@@ -60,6 +63,7 @@ try-runtime = [
 	"frame-support/try-runtime",
 	"frame-system/try-runtime",
 	"pallet-authorship/try-runtime",
+	"pallet-balances/try-runtime",
 	"pallet-session/try-runtime",
 	"sp-runtime/try-runtime",
 ]
diff --git a/substrate/frame/im-online/src/mock.rs b/substrate/frame/im-online/src/mock.rs
index 80834c68a216b..06446cbac1439 100644
--- a/substrate/frame/im-online/src/mock.rs
+++ b/substrate/frame/im-online/src/mock.rs
@@ -40,6 +40,7 @@ frame_support::construct_runtime!(
 	pub enum Runtime {
 		System: frame_system,
 		Session: pallet_session,
+		Balances: pallet_balances,
 		ImOnline: imonline,
 		Historical: pallet_session_historical,
 	}
@@ -109,9 +110,15 @@ pub fn new_test_ext() -> sp_io::TestExternalities {
 
 #[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
 impl frame_system::Config for Runtime {
+	type AccountData = pallet_balances::AccountData<u64>;
 	type Block = Block;
 }
 
+#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig)]
+impl pallet_balances::Config for Runtime {
+	type AccountStore = System;
+}
+
 parameter_types! {
 	pub const Period: u64 = 1;
 	pub const Offset: u64 = 0;
@@ -129,6 +136,8 @@ impl pallet_session::Config for Runtime {
 	type NextSessionRotation = pallet_session::PeriodicSessions<Period, Offset>;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Runtime {
diff --git a/substrate/frame/offences/benchmarking/src/mock.rs b/substrate/frame/offences/benchmarking/src/mock.rs
index 61a8cf53533a9..7b2ddf26228a3 100644
--- a/substrate/frame/offences/benchmarking/src/mock.rs
+++ b/substrate/frame/offences/benchmarking/src/mock.rs
@@ -97,6 +97,8 @@ impl pallet_session::Config for Test {
 	type ValidatorIdOf = sp_runtime::traits::ConvertInto;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 pallet_staking_reward_curve::build! {
diff --git a/substrate/frame/root-offences/src/mock.rs b/substrate/frame/root-offences/src/mock.rs
index ffe4367e8b810..1a3627fca7b38 100644
--- a/substrate/frame/root-offences/src/mock.rs
+++ b/substrate/frame/root-offences/src/mock.rs
@@ -168,6 +168,8 @@ impl pallet_session::Config for Test {
 	type NextSessionRotation = pallet_session::PeriodicSessions<Period, Offset>;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_timestamp::Config for Test {
diff --git a/substrate/frame/session/Cargo.toml b/substrate/frame/session/Cargo.toml
index 737678bea8a3b..18905d6a56a2d 100644
--- a/substrate/frame/session/Cargo.toml
+++ b/substrate/frame/session/Cargo.toml
@@ -21,6 +21,7 @@ frame-support = { workspace = true }
 frame-system = { workspace = true }
 impl-trait-for-tuples = { workspace = true }
 log = { workspace = true }
+pallet-balances = { workspace = true }
 pallet-timestamp = { workspace = true }
 scale-info = { features = ["derive", "serde"], workspace = true }
 sp-core = { features = ["serde"], workspace = true }
@@ -39,6 +40,7 @@ std = [
 	"frame-support/std",
 	"frame-system/std",
 	"log/std",
+	"pallet-balances/std",
 	"pallet-timestamp/std",
 	"scale-info/std",
 	"sp-core/std",
@@ -52,6 +54,7 @@ std = [
 try-runtime = [
 	"frame-support/try-runtime",
 	"frame-system/try-runtime",
+	"pallet-balances/try-runtime",
 	"pallet-timestamp/try-runtime",
 	"sp-runtime/try-runtime",
 ]
diff --git a/substrate/frame/session/README.md b/substrate/frame/session/README.md
index 5a063bffee0b1..6d1d4611f67e9 100644
--- a/substrate/frame/session/README.md
+++ b/substrate/frame/session/README.md
@@ -23,10 +23,12 @@ same as the account ID. For staking systems using a stash/controller model, the
 ID of the controller.
 - **Session key configuration process:** Session keys are set using `set_keys` for use not in the next session, but the
 session after next. They are stored in `NextKeys`, a mapping between the caller's `ValidatorId` and the session keys
-provided. `set_keys` allows users to set their session key prior to being selected as validator. It is a public call
-since it uses `ensure_signed`, which checks that the origin is a signed account. As such, the account ID of the origin
-stored in `NextKeys` may not necessarily be associated with a block author or a validator. The session keys of accounts
-are removed once their account balance is zero.
+provided. `set_keys` allows users to set their session key prior to being selected as validator. When setting keys, a deposit
+is required and reserved from the account. The account must have sufficient funds available for this deposit, or the
+operation will fail. This deposit is returned when the keys are purged. `set_keys` is a public call since it uses
+`ensure_signed`, which checks that the origin is a signed account. As such, the account ID of the origin stored in
+`NextKeys` may not necessarily be associated with a block author or a validator. The session keys of accounts are removed
+once their account balance is zero.
 - **Session length:** This pallet does not assume anything about the length of each session. Rather, it relies on an
 implementation of `ShouldEndSession` to dictate a new session's start. This pallet provides the `PeriodicSessions`
 struct for simple periodic sessions.
@@ -70,7 +72,7 @@ set.
 use pallet_session as session;
 
 fn validators<T: pallet_session::Config>() -> Vec<<T as pallet_session::Config>::ValidatorId> {
-	pallet_session::Validators::<T>::get()
+ pallet_session::Validators::<T>::get()
 }
 ```
 
diff --git a/substrate/frame/session/benchmarking/src/mock.rs b/substrate/frame/session/benchmarking/src/mock.rs
index d4003004628e5..288bf56ad25ee 100644
--- a/substrate/frame/session/benchmarking/src/mock.rs
+++ b/substrate/frame/session/benchmarking/src/mock.rs
@@ -106,6 +106,8 @@ impl pallet_session::Config for Test {
 	type ValidatorIdOf = sp_runtime::traits::ConvertInto;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 pallet_staking_reward_curve::build! {
 	const I_NPOS: sp_runtime::curve::PiecewiseLinear<'static> = curve!(
diff --git a/substrate/frame/session/src/lib.rs b/substrate/frame/session/src/lib.rs
index 45ef1ac4f100c..bfa7540132293 100644
--- a/substrate/frame/session/src/lib.rs
+++ b/substrate/frame/session/src/lib.rs
@@ -129,6 +129,7 @@ use frame_support::{
 	dispatch::DispatchResult,
 	ensure,
 	traits::{
+		fungible::{hold::Mutate as HoldMutate, Inspect},
 		Defensive, EstimateNextNewSession, EstimateNextSessionRotation, FindAuthor, Get,
 		OneSessionHandler, ValidatorRegistration, ValidatorSet,
 	},
@@ -415,6 +416,10 @@ pub mod pallet {
 
 		/// A conversion from account ID to validator ID.
 		///
+		/// It is also a means to check that an account id is eligible to set session keys, through
+		/// being associated with a validator id. To disable this check, use
+		/// [`sp_runtime::traits::ConvertInto`].
+		///
 		/// Its cost must be at most one storage read.
 		type ValidatorIdOf: Convert<Self::AccountId, Option<Self::ValidatorId>>;
 
@@ -440,6 +445,16 @@ pub mod pallet {
 
 		/// Weight information for extrinsics in this pallet.
 		type WeightInfo: WeightInfo;
+
+		/// The currency type for placing holds when setting keys.
+		type Currency: Inspect<Self::AccountId>
+			+ HoldMutate<Self::AccountId, Reason: From<HoldReason>>;
+
+		/// The amount to be held when setting keys.
+		#[pallet::constant]
+		type KeyDeposit: Get<
+			<<Self as Config>::Currency as Inspect<<Self as frame_system::Config>::AccountId>>::Balance,
+		>;
 	}
 
 	#[pallet::genesis_config]
@@ -516,6 +531,14 @@ pub mod pallet {
 		}
 	}
 
+	/// A reason for the pallet placing a hold on funds.
+	#[pallet::composite_enum]
+	pub enum HoldReason {
+		// Funds are held when settings keys
+		#[codec(index = 0)]
+		Keys,
+	}
+
 	/// The current set of validators.
 	#[pallet::storage]
 	pub type Validators<T: Config> = StorageValue<_, Vec<T::ValidatorId>, ValueQuery>;
@@ -823,8 +846,17 @@ impl<T: Config> Pallet<T> {
 			.ok_or(Error::<T>::NoAssociatedValidatorId)?;
 
 		ensure!(frame_system::Pallet::<T>::can_inc_consumer(account), Error::<T>::NoAccount);
+
 		let old_keys = Self::inner_set_keys(&who, keys)?;
+
+		// Place deposit on hold if this is a new registration (i.e. old_keys is None).
+		// The hold call itself will return an error if funds are insufficient.
 		if old_keys.is_none() {
+			let deposit = T::KeyDeposit::get();
+			if !deposit.is_zero() {
+				T::Currency::hold(&HoldReason::Keys.into(), account, deposit)?;
+			}
+
 			let assertion = frame_system::Pallet::<T>::inc_consumers(account).is_ok();
 			debug_assert!(assertion, "can_inc_consumer() returned true; no change since; qed");
 		}
@@ -885,6 +917,14 @@ impl<T: Config> Pallet<T> {
 			let key_data = old_keys.get_raw(*id);
 			Self::clear_key_owner(*id, key_data);
 		}
+
+		// Use release_all to handle the case where the exact amount might not be available
+		let _ = T::Currency::release_all(
+			&HoldReason::Keys.into(),
+			account,
+			frame_support::traits::tokens::Precision::BestEffort,
+		);
+
 		frame_system::Pallet::<T>::dec_consumers(account);
 
 		Ok(())
diff --git a/substrate/frame/session/src/mock.rs b/substrate/frame/session/src/mock.rs
index 1a5fcdc9b6579..ff85c4e2f2730 100644
--- a/substrate/frame/session/src/mock.rs
+++ b/substrate/frame/session/src/mock.rs
@@ -21,15 +21,17 @@ use super::*;
 use crate as pallet_session;
 #[cfg(feature = "historical")]
 use crate::historical as pallet_session_historical;
-
-use std::collections::BTreeMap;
-
+use frame_support::{derive_impl, parameter_types, traits::ConstU64};
+use pallet_balances::{self, AccountData};
 use sp_core::crypto::key_types::DUMMY;
-use sp_runtime::{impl_opaque_keys, testing::UintAuthorityId, BuildStorage};
+use sp_runtime::{
+	impl_opaque_keys,
+	testing::UintAuthorityId,
+	traits::{Convert, OpaqueKeys},
+	BuildStorage,
+};
 use sp_staking::SessionIndex;
-use sp_state_machine::BasicExternalities;
-
-use frame_support::{derive_impl, parameter_types, traits::ConstU64};
+use std::collections::BTreeMap;
 
 impl_opaque_keys! {
 	pub struct MockSessionKeys {
@@ -76,6 +78,7 @@ frame_support::construct_runtime!(
 	{
 		System: frame_system,
 		Session: pallet_session,
+		Balances: pallet_balances,
 		Historical: pallet_session_historical,
 	}
 );
@@ -86,6 +89,7 @@ frame_support::construct_runtime!(
 	{
 		System: frame_system,
 		Session: pallet_session,
+		Balances: pallet_balances,
 	}
 );
 
@@ -102,6 +106,7 @@ parameter_types! {
 	// Stores if `on_before_session_end` was called
 	pub static BeforeSessionEndCalled: bool = false;
 	pub static ValidatorAccounts: BTreeMap<u64, u64> = BTreeMap::new();
+	pub static KeyDeposit: u64 = 10;
 }
 
 pub struct TestShouldEndSession;
@@ -200,21 +205,48 @@ pub fn reset_before_session_end_called() {
 	BeforeSessionEndCalled::mutate(|b| *b = false);
 }
 
+parameter_types! {
+	pub static LastSessionEventIndex: usize = 0;
+}
+
+pub fn session_events_since_last_call() -> Vec<pallet_session::Event<Test>> {
+	let events = System::read_events_for_pallet::<pallet_session::Event<Test>>();
+	let already_seen = LastSessionEventIndex::get();
+	LastSessionEventIndex::set(events.len());
+	events.into_iter().skip(already_seen).collect()
+}
+
+pub fn session_hold(who: u64) -> u64 {
+	<Balances as frame_support::traits::fungible::InspectHold<_>>::balance_on_hold(
+		&crate::HoldReason::Keys.into(),
+		&who,
+	)
+}
+
 pub fn new_test_ext() -> sp_io::TestExternalities {
 	let mut t = frame_system::GenesisConfig::<Test>::default().build_storage().unwrap();
+	let ed = <Test as pallet_balances::Config>::ExistentialDeposit::get();
+	pallet_balances::GenesisConfig::<Test> {
+		balances: vec![
+			(1, (KeyDeposit::get() * 10).max(ed)),
+			(2, (KeyDeposit::get() * 10).max(ed)),
+			(3, (KeyDeposit::get() * 10).max(ed)),
+			(4, (KeyDeposit::get() * 10).max(ed)),
+			(69, (KeyDeposit::get() * 10).max(ed)),
+			// one account who does not have enough balance to pay the key deposit
+			(999, (KeyDeposit::get().saturating_sub(1)).max(ed)),
+			(1000, (KeyDeposit::get() * 10).max(ed)),
+		],
+		dev_accounts: None,
+	}
+	.assimilate_storage(&mut t)
+	.unwrap();
+
 	let keys: Vec<_> = NextValidators::get()
 		.iter()
 		.cloned()
 		.map(|i| (i, i, UintAuthorityId(i).into()))
 		.collect();
-	BasicExternalities::execute_with_storage(&mut t, || {
-		for (ref k, ..) in &keys {
-			frame_system::Pallet::<Test>::inc_providers(k);
-		}
-		frame_system::Pallet::<Test>::inc_providers(&4);
-		// An additional identity that we use.
-		frame_system::Pallet::<Test>::inc_providers(&69);
-	});
 	pallet_session::GenesisConfig::<Test> { keys, ..Default::default() }
 		.assimilate_storage(&mut t)
 		.unwrap();
@@ -227,6 +259,8 @@ pub fn new_test_ext() -> sp_io::TestExternalities {
 #[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
 impl frame_system::Config for Test {
 	type Block = Block;
+	type AccountData = AccountData<u64>;
+	type RuntimeEvent = RuntimeEvent;
 }
 
 impl pallet_timestamp::Config for Test {
@@ -267,6 +301,8 @@ impl Config for Test {
 	type DisablingStrategy =
 		disabling::UpToLimitWithReEnablingDisablingStrategy<DISABLING_LIMIT_FACTOR>;
 	type WeightInfo = ();
+	type Currency = pallet_balances::Pallet<Test>;
+	type KeyDeposit = KeyDeposit;
 }
 
 #[cfg(feature = "historical")]
@@ -275,3 +311,9 @@ impl crate::historical::Config for Test {
 	type FullIdentification = u64;
 	type FullIdentificationOf = sp_runtime::traits::ConvertInto;
 }
+
+#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig as pallet_balances::DefaultConfig)]
+impl pallet_balances::Config for Test {
+	type AccountStore = System;
+	type RuntimeEvent = RuntimeEvent;
+}
diff --git a/substrate/frame/session/src/tests.rs b/substrate/frame/session/src/tests.rs
index 245524a2e5989..4a749b0a7817a 100644
--- a/substrate/frame/session/src/tests.rs
+++ b/substrate/frame/session/src/tests.rs
@@ -20,9 +20,10 @@
 use super::*;
 use crate::mock::{
 	authorities, before_session_end_called, force_new_session, new_test_ext,
-	reset_before_session_end_called, session_changed, set_next_validators, set_session_length,
+	reset_before_session_end_called, session_changed, session_events_since_last_call, session_hold,
+	set_next_validators, set_session_length, Balances, KeyDeposit, MockSessionKeys,
 	PreUpgradeMockSessionKeys, RuntimeOrigin, Session, SessionChanged, System, Test,
-	TestSessionChanged, TestValidatorIdOf,
+	TestSessionChanged, TestValidatorIdOf, ValidatorAccounts,
 };
 
 use codec::Decode;
@@ -30,7 +31,7 @@ use sp_core::crypto::key_types::DUMMY;
 use sp_runtime::{testing::UintAuthorityId, Perbill};
 
 use frame_support::{
-	assert_noop, assert_ok,
+	assert_err, assert_noop, assert_ok,
 	traits::{ConstU64, OnInitialize},
 };
 
@@ -187,27 +188,42 @@ fn session_change_should_work() {
 		// Block 1: No change
 		initialize_block(1);
 		assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+		assert_eq!(session_events_since_last_call(), vec![]);
 
 		// Block 2: Session rollover, but no change.
 		initialize_block(2);
 		assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+		assert_eq!(
+			session_events_since_last_call(),
+			vec![Event::NewQueued, Event::NewSession { session_index: 1 }]
+		);
 
 		// Block 3: Set new key for validator 2; no visible change.
 		initialize_block(3);
 		assert_ok!(Session::set_keys(RuntimeOrigin::signed(2), UintAuthorityId(5).into(), vec![]));
 		assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+		assert_eq!(session_events_since_last_call(), vec![]);
 
 		// Block 4: Session rollover; no visible change.
 		initialize_block(4);
 		assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+		assert_eq!(
+			session_events_since_last_call(),
+			vec![Event::NewQueued, Event::NewSession { session_index: 2 }]
+		);
 
 		// Block 5: No change.
 		initialize_block(5);
 		assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+		assert_eq!(session_events_since_last_call(), vec![]);
 
 		// Block 6: Session rollover; authority 2 changes.
 		initialize_block(6);
 		assert_eq!(authorities(), vec![UintAuthorityId(1), UintAuthorityId(5), UintAuthorityId(3)]);
+		assert_eq!(
+			session_events_since_last_call(),
+			vec![Event::NewQueued, Event::NewSession { session_index: 3 }]
+		);
 	});
 }
 
@@ -467,6 +483,113 @@ fn test_migration_v1() {
 	});
 }
 
+#[test]
+fn set_keys_should_fail_with_insufficient_funds() {
+	new_test_ext().execute_with(|| {
+		// Account 999 is mocked to have KeyDeposit -1
+		let account_id = 999;
+		let keys = MockSessionKeys { dummy: UintAuthorityId(account_id).into() };
+		frame_system::Pallet::<Test>::inc_providers(&account_id);
+		// Make sure we have a validator ID
+		ValidatorAccounts::mutate(|m| {
+			m.insert(account_id, account_id);
+		});
+
+		// Attempt to set keys with an account that has insufficient funds
+		// Should fail with Err(Token(FundsUnavailable)) from `pallet-balances`
+		assert_err!(
+			Session::set_keys(RuntimeOrigin::signed(account_id), keys, vec![]),
+			sp_runtime::TokenError::FundsUnavailable
+		);
+	});
+}
+
+#[test]
+fn set_keys_should_hold_funds() {
+	new_test_ext().execute_with(|| {
+		// Account 1000 is mocked to have sufficient funds
+		let account_id = 1000;
+		let keys = MockSessionKeys { dummy: UintAuthorityId(account_id).into() };
+		let deposit = KeyDeposit::get();
+
+		// Make sure we have a validator ID
+		ValidatorAccounts::mutate(|m| {
+			m.insert(account_id, account_id);
+		});
+
+		// Set keys and check the operation succeeds
+		let res = Session::set_keys(RuntimeOrigin::signed(account_id), keys, vec![]);
+		assert_ok!(res);
+
+		// Check that the funds are held
+		assert_eq!(session_hold(account_id), deposit);
+	});
+}
+
+#[test]
+fn purge_keys_should_unhold_funds() {
+	new_test_ext().execute_with(|| {
+		// Account 1000 is mocked to have sufficient funds
+		let account_id = 1000;
+		let keys = MockSessionKeys { dummy: UintAuthorityId(account_id).into() };
+		let deposit = KeyDeposit::get();
+
+		// Make sure we have a validator ID
+		ValidatorAccounts::mutate(|m| {
+			m.insert(account_id, account_id);
+		});
+
+		// Ensure system providers are properly set for the test account
+		frame_system::Pallet::<Test>::inc_providers(&account_id);
+
+		// First set the keys to reserve the deposit
+		let res = Session::set_keys(RuntimeOrigin::signed(account_id), keys, vec![]);
+		assert_ok!(res);
+
+		// Check the reserved balance after setting keys
+		let reserved_balance_before_purge = Balances::reserved_balance(&account_id);
+		assert!(
+			reserved_balance_before_purge >= deposit,
+			"Deposit should be reserved after setting keys"
+		);
+
+		// Now purge the keys
+		let res = Session::purge_keys(RuntimeOrigin::signed(account_id));
+		assert_ok!(res);
+
+		// Check that the funds were unreserved
+		let reserved_balance_after_purge = Balances::reserved_balance(&account_id);
+		assert_eq!(reserved_balance_after_purge, reserved_balance_before_purge - deposit);
+	});
+}
+
+#[test]
+fn existing_validators_without_hold_are_except() {
+	// upon addition of `SessionDeposit`, a runtime may have some old validators without any held
+	// amount. They can freely still update their session keys. They can also purge them.
+
+	// disable key deposit for initial validators
+	KeyDeposit::set(0);
+	new_test_ext().execute_with(|| {
+		// reset back to the first value.
+		KeyDeposit::set(10);
+		// 1 is an initial validator
+		assert_eq!(session_hold(1), 0);
+
+		// upgrade 1's keys
+		assert_ok!(Session::set_keys(
+			RuntimeOrigin::signed(1),
+			UintAuthorityId(7).into(),
+			Default::default()
+		));
+		assert_eq!(session_hold(1), 0);
+
+		// purge 1's keys
+		assert_ok!(Session::purge_keys(RuntimeOrigin::signed(1)));
+		assert_eq!(session_hold(1), 0);
+	});
+}
+
 mod disabling_byzantine_threshold {
 	use super::*;
 	use crate::disabling::{DisablingStrategy, UpToLimitDisablingStrategy};
diff --git a/substrate/frame/staking-async/ahm-test/src/rc/mock.rs b/substrate/frame/staking-async/ahm-test/src/rc/mock.rs
index 128d0a1150e12..1386debdd3c8f 100644
--- a/substrate/frame/staking-async/ahm-test/src/rc/mock.rs
+++ b/substrate/frame/staking-async/ahm-test/src/rc/mock.rs
@@ -179,6 +179,8 @@ impl pallet_session::Config for Runtime {
 	type SessionManager = pallet_session::historical::NoteHistoricalRoot<Self, StakingAhClient>;
 
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 parameter_types! {
diff --git a/substrate/frame/staking-async/runtimes/parachain/src/lib.rs b/substrate/frame/staking-async/runtimes/parachain/src/lib.rs
index e069e032f3c9a..b595910c52dfa 100644
--- a/substrate/frame/staking-async/runtimes/parachain/src/lib.rs
+++ b/substrate/frame/staking-async/runtimes/parachain/src/lib.rs
@@ -908,6 +908,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_aura::Config for Runtime {
diff --git a/substrate/frame/staking-async/runtimes/rc/src/lib.rs b/substrate/frame/staking-async/runtimes/rc/src/lib.rs
index c02c7ebaa8e7e..8ca28426fbf31 100644
--- a/substrate/frame/staking-async/runtimes/rc/src/lib.rs
+++ b/substrate/frame/staking-async/runtimes/rc/src/lib.rs
@@ -565,6 +565,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = pallet_session::disabling::UpToLimitWithReEnablingDisablingStrategy;
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl session_historical::Config for Runtime {
diff --git a/substrate/frame/staking/src/mock.rs b/substrate/frame/staking/src/mock.rs
index 732c23562300c..aaec1d15c7416 100644
--- a/substrate/frame/staking/src/mock.rs
+++ b/substrate/frame/staking/src/mock.rs
@@ -151,6 +151,8 @@ impl pallet_session::Config for Test {
 	type DisablingStrategy =
 		pallet_session::disabling::UpToLimitWithReEnablingDisablingStrategy<DISABLING_LIMIT_FACTOR>;
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 impl pallet_session::historical::Config for Test {
diff --git a/templates/parachain/runtime/src/configs/mod.rs b/templates/parachain/runtime/src/configs/mod.rs
index 70f343a23f458..a15a2c6d8bc4b 100644
--- a/templates/parachain/runtime/src/configs/mod.rs
+++ b/templates/parachain/runtime/src/configs/mod.rs
@@ -277,6 +277,8 @@ impl pallet_session::Config for Runtime {
 	type Keys = SessionKeys;
 	type DisablingStrategy = ();
 	type WeightInfo = ();
+	type Currency = Balances;
+	type KeyDeposit = ();
 }
 
 #[docify::export(aura_config)]