diff --git a/core/src/config/extrinsic_params.rs b/core/src/config/extrinsic_params.rs
index 89b926aa06f..45f1c17489d 100644
--- a/core/src/config/extrinsic_params.rs
+++ b/core/src/config/extrinsic_params.rs
@@ -81,12 +81,11 @@ impl<T: Config> Params<T> for () {}
 
 macro_rules! impl_tuples {
     ($($ident:ident $index:tt),+) => {
-
-        impl <T: Config, $($ident : Params<T>),+> Params<T> for ($($ident,)+){
+        impl <Conf: Config, $($ident : Params<Conf>),+> Params<Conf> for ($($ident,)+){
             fn inject_account_nonce(&mut self, nonce: u64) {
                 $(self.$index.inject_account_nonce(nonce);)+
             }
-            fn inject_block(&mut self, number: u64, hash: T::Hash) {
+            fn inject_block(&mut self, number: u64, hash: Conf::Hash) {
                 $(self.$index.inject_block(number, hash);)+
             }
         }
@@ -114,6 +113,11 @@ const _: () = {
     impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16);
     impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17);
     impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18);
-    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, U 19);
-    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, U 19, V 20);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19, U 20);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19, U 20, V 21);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19, U 20, V 21, W 22);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19, U 20, V 21, W 22, X 23);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19, U 20, V 21, W 22, X 23, Y 24);
+    impl_tuples!(A 0, B 1, C 2, D 3, E 4, F 5, G 6, H 7, I 8, J 9, K 10, L 11, M 12, N 13, O 14, P 15, Q 16, R 17, S 18, T 19, U 20, V 21, W 22, X 23, Y 24, Z 25);
 };
diff --git a/subxt/src/tx/mod.rs b/subxt/src/tx/mod.rs
index a920e644c2e..98f5bd59515 100644
--- a/subxt/src/tx/mod.rs
+++ b/subxt/src/tx/mod.rs
@@ -15,7 +15,7 @@ mod tx_progress;
 pub use subxt_core::tx::payload::{dynamic, DefaultPayload, DynamicPayload, Payload};
 pub use subxt_core::tx::signer::{self, Signer};
 pub use tx_client::{
-    PartialTransaction, SubmittableTransaction, TransactionInvalid, TransactionUnknown, TxClient,
-    ValidationResult,
+    DefaultParams, PartialTransaction, SubmittableTransaction, TransactionInvalid,
+    TransactionUnknown, TxClient, ValidationResult,
 };
 pub use tx_progress::{TxInBlock, TxProgress, TxStatus};
diff --git a/subxt/src/tx/tx_client.rs b/subxt/src/tx/tx_client.rs
index 41ddc0ae956..1dbf0aa82d9 100644
--- a/subxt/src/tx/tx_client.rs
+++ b/subxt/src/tx/tx_client.rs
@@ -281,9 +281,9 @@ where
     where
         Call: Payload,
         Signer: SignerT<T>,
-        <T::ExtrinsicParams as ExtrinsicParams<T>>::Params: Default,
+        <T::ExtrinsicParams as ExtrinsicParams<T>>::Params: DefaultParams,
     {
-        self.sign_and_submit_then_watch(call, signer, Default::default())
+        self.sign_and_submit_then_watch(call, signer, DefaultParams::default_params())
             .await
     }
 
@@ -325,9 +325,10 @@ where
     where
         Call: Payload,
         Signer: SignerT<T>,
-        <T::ExtrinsicParams as ExtrinsicParams<T>>::Params: Default,
+        <T::ExtrinsicParams as ExtrinsicParams<T>>::Params: DefaultParams,
     {
-        self.sign_and_submit(call, signer, Default::default()).await
+        self.sign_and_submit(call, signer, DefaultParams::default_params())
+            .await
     }
 
     /// Creates and signs an transaction and submits to the chain for block inclusion.
@@ -514,7 +515,7 @@ where
         match sub.next().await {
             Some(Ok(status)) => match status {
                 TransactionStatus::Validated
-                | TransactionStatus::Broadcasted { .. }
+                | TransactionStatus::Broadcasted
                 | TransactionStatus::InBestBlock { .. }
                 | TransactionStatus::NoLongerInBestBlock
                 | TransactionStatus::InFinalizedBlock { .. } => Ok(ext_hash),
@@ -754,6 +755,67 @@ pub enum TransactionInvalid {
     BadSigner,
 }
 
+/// This trait is used to create default values for extrinsic params. We use this instead of
+/// [`Default`] because we want to be able to support params which are tuples of more than 12
+/// entries (which is the maximum tuple size Rust currently implements [`Default`] for on tuples),
+/// given that we aren't far off having more than 12 transaction extensions already.
+///
+/// If you have params which are _not_ a tuple and which you'd like to be instantiated automatically
+/// when calling [`TxClient::sign_and_submit_default()`] or [`TxClient::sign_and_submit_then_watch_default()`],
+/// then you'll need to implement this trait for them.
+pub trait DefaultParams: Sized {
+    /// Instantiate a default instance of the parameters.
+    fn default_params() -> Self;
+}
+
+impl<const N: usize, P: Default> DefaultParams for [P; N] {
+    fn default_params() -> Self {
+        core::array::from_fn(|_| P::default())
+    }
+}
+
+macro_rules! impl_default_params_for_tuple {
+    ($($ident:ident),+) => {
+        impl <$($ident : Default),+> DefaultParams for ($($ident,)+){
+            fn default_params() -> Self {
+                (
+                    $($ident::default(),)+
+                )
+            }
+        }
+    }
+}
+
+#[rustfmt::skip]
+const _: () = {
+    impl_default_params_for_tuple!(A);
+    impl_default_params_for_tuple!(A, B);
+    impl_default_params_for_tuple!(A, B, C);
+    impl_default_params_for_tuple!(A, B, C, D);
+    impl_default_params_for_tuple!(A, B, C, D, E);
+    impl_default_params_for_tuple!(A, B, C, D, E, F);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y);
+    impl_default_params_for_tuple!(A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z);
+};
+
 #[cfg(test)]
 mod test {
     use super::*;