diff --git a/core/txpool/errors.go b/core/txpool/errors.go
index a4ed6a14986b..8911e59676c3 100644
--- a/core/txpool/errors.go
+++ b/core/txpool/errors.go
@@ -59,6 +59,12 @@ var (
 	// transaction. Future transactions should only be able to replace other future transactions.
 	ErrFutureReplacePending = errors.New("future transaction tries to replace pending")
 
+	// ErrAlreadyReserved is returned if the sender address has a pending transaction
+	// in a different subpool. For example, this error is returned in response to any
+	// input transaction of non-blob type when a blob transaction from this sender
+	// remains pending (and vice-versa).
+	ErrAlreadyReserved = errors.New("address already reserved")
+
 	ErrZeroGasPrice = errors.New("zero gas price")
 
 	ErrUnderMinGasPrice = errors.New("under min gas price")
diff --git a/core/txpool/txpool.go b/core/txpool/txpool.go
index 630d48aeb790..9d49d431e027 100644
--- a/core/txpool/txpool.go
+++ b/core/txpool/txpool.go
@@ -118,7 +118,7 @@ func (p *TxPool) reserver(id int, subpool SubPool) AddressReserver {
 					log.Error("pool attempted to reserve already-owned address", "address", addr)
 					return nil // Ignore fault to give the pool a chance to recover while the bug gets fixed
 				}
-				return errors.New("address already reserved")
+				return ErrAlreadyReserved
 			}
 			p.reservations[addr] = subpool
 			if metrics.Enabled() {