diff --git a/auctioneer/errors.go b/auctioneer/errors.go
new file mode 100644
index 0000000..2fc658b
--- /dev/null
+++ b/auctioneer/errors.go
@@ -0,0 +1,74 @@
+package auctioneer
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/btcsuite/btcutil"
+	"github.com/lightninglabs/llm/clmrpc"
+)
+
+var (
+	// ErrAcctResNotCompleted is the error wrapped by
+	// AcctResNotCompletedError that can be used with errors.Is() to
+	// avoid type assertions.
+	ErrAcctResNotCompleted = errors.New("account reservation not completed")
+)
+
+// AcctResNotCompletedError is returned if a trader tries to subscribe to an account
+// that we don't know. This should only happen during recovery where the trader
+// goes through a number of their keys to find accounts we still know the state
+// of.
+type AcctResNotCompletedError struct {
+	// Value is the value of the account reflected in the on-chain output
+	// that backs the existence of an account.
+	Value btcutil.Amount
+
+	// AcctKey is the raw account key of the account we didn't find in our
+	// database.
+	AcctKey [33]byte
+
+	// AuctioneerKey is the raw base auctioneer's key in the 2-of-2
+	// multi-sig construction of a CLM account.
+	AuctioneerKey [33]byte
+
+	// InitialBatchKey is the raw initial batch key that is used to tweak
+	// the trader key of an account.
+	InitialBatchKey [33]byte
+
+	// HeightHint is the block height at the time of the reservation. Even
+	// if the transaction was published, it cannot have happened in an
+	// earlier block.
+	HeightHint uint32
+
+	// Expiry is the expiration block height of an account. After this
+	// point, the trader is able to withdraw the funds from their account
+	// without cooperation of the auctioneer.
+	Expiry uint32
+}
+
+// Error implements the error interface.
+func (e *AcctResNotCompletedError) Error() string {
+	return fmt.Sprintf("account %x reservation not completed", e.AcctKey)
+}
+
+// Unwrap returns the underlying error type.
+func (e *AcctResNotCompletedError) Unwrap() error {
+	return ErrAcctResNotCompleted
+}
+
+// AcctResNotCompletedErrFromRPC creates a new AcctResNotCompletedError from an
+// RPC account message.
+func AcctResNotCompletedErrFromRPC(
+	rpcAcc clmrpc.AuctionAccount) *AcctResNotCompletedError {
+
+	result := &AcctResNotCompletedError{
+		Value:      btcutil.Amount(rpcAcc.Value),
+		Expiry:     rpcAcc.Expiry,
+		HeightHint: rpcAcc.HeightHint,
+	}
+	copy(result.AcctKey[:], rpcAcc.TraderKey)
+	copy(result.AuctioneerKey[:], rpcAcc.AuctioneerKey)
+	copy(result.InitialBatchKey[:], rpcAcc.BatchKey)
+	return result
+}