diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5faae3fed7fa..a29245b06985 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -68,6 +68,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [#12455](https://github.com/cosmos/cosmos-sdk/pull/12455) Show attempts count in error for signing. 
 * [#12886](https://github.com/cosmos/cosmos-sdk/pull/12886) Amortize cost of processing cache KV store
 * [#12953](https://github.com/cosmos/cosmos-sdk/pull/12953) Change the default priority mechanism to be based on gas price.
+* [#13048](https://github.com/cosmos/cosmos-sdk/pull/13048) Add handling of AccountNumberStoreKeyPrefix to the x/auth simulation decoder.
 
 ### State Machine Breaking
 
diff --git a/x/auth/simulation/decoder.go b/x/auth/simulation/decoder.go
index 61a551ba5208..df4a202744f1 100644
--- a/x/auth/simulation/decoder.go
+++ b/x/auth/simulation/decoder.go
@@ -7,6 +7,7 @@ import (
 	gogotypes "github.com/gogo/protobuf/types"
 
 	"github.com/cosmos/cosmos-sdk/codec"
+	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/kv"
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
 )
@@ -41,6 +42,20 @@ func NewDecodeStore(ak AuthUnmarshaler) func(kvA, kvB kv.Pair) string {
 
 			return fmt.Sprintf("GlobalAccNumberA: %d\nGlobalAccNumberB: %d", globalAccNumberA, globalAccNumberB)
 
+		case bytes.HasPrefix(kvA.Key, types.AccountNumberStoreKeyPrefix):
+			var accNumA, accNumB sdk.AccAddress
+			err := accNumA.Unmarshal(kvA.Value)
+			if err != nil {
+				panic(err)
+			}
+
+			err = accNumB.Unmarshal(kvB.Value)
+			if err != nil {
+				panic(err)
+			}
+
+			return fmt.Sprintf("AccNumA: %s\nAccNumB: %s", accNumA, accNumB)
+
 		default:
 			panic(fmt.Sprintf("unexpected %s key %X (%s)", types.ModuleName, kvA.Key, kvA.Key))
 		}
diff --git a/x/auth/simulation/decoder_test.go b/x/auth/simulation/decoder_test.go
index efc7dcc461c4..021360070e04 100644
--- a/x/auth/simulation/decoder_test.go
+++ b/x/auth/simulation/decoder_test.go
@@ -51,6 +51,10 @@ func TestDecodeStore(t *testing.T) {
 				Key:   types.GlobalAccountNumberKey,
 				Value: cdc.MustMarshal(&globalAccNumber),
 			},
+			{
+				Key:   types.AccountNumberStoreKey(5),
+				Value: acc.GetAddress().Bytes(),
+			},
 			{
 				Key:   []byte{0x99},
 				Value: []byte{0x99},
@@ -63,6 +67,7 @@ func TestDecodeStore(t *testing.T) {
 	}{
 		{"Account", fmt.Sprintf("%v\n%v", acc, acc)},
 		{"GlobalAccNumber", fmt.Sprintf("GlobalAccNumberA: %d\nGlobalAccNumberB: %d", globalAccNumber, globalAccNumber)},
+		{"AccNum", fmt.Sprintf("AccNumA: %s\nAccNumB: %s", acc.GetAddress(), acc.GetAddress())},
 		{"other", ""},
 	}