diff --git a/crypto/address.go b/crypto/address.go
index fd26b6e46..09b1bb356 100644
--- a/crypto/address.go
+++ b/crypto/address.go
@@ -99,13 +99,10 @@ func (addr Address) String() string {
 		return treasuryAddressString
 	}
 
-	str, err := bech32m.EncodeFromBase256WithType(
+	str, _ := bech32m.EncodeFromBase256WithType(
 		AddressHRP,
 		addr[0],
 		addr[1:])
-	if err != nil {
-		panic(err.Error())
-	}
 
 	return str
 }
diff --git a/state/mock.go b/state/mock.go
index 3d9d51d5e..49bf929be 100644
--- a/state/mock.go
+++ b/state/mock.go
@@ -21,7 +21,6 @@ import (
 	"github.com/pactus-project/pactus/types/tx/payload"
 	"github.com/pactus-project/pactus/types/validator"
 	"github.com/pactus-project/pactus/types/vote"
-	"github.com/pactus-project/pactus/util/errors"
 	"github.com/pactus-project/pactus/util/testsuite"
 )
 
@@ -233,18 +232,10 @@ func (m *MockState) PendingTx(id tx.ID) *tx.Tx {
 }
 
 func (m *MockState) AddPendingTx(trx *tx.Tx) error {
-	if m.TestPool.HasTx(trx.ID()) {
-		return errors.Error(errors.ErrGeneric)
-	}
-
 	return m.TestPool.AppendTx(trx)
 }
 
 func (m *MockState) AddPendingTxAndBroadcast(trx *tx.Tx) error {
-	if m.TestPool.HasTx(trx.ID()) {
-		return errors.Error(errors.ErrGeneric)
-	}
-
 	return m.TestPool.AppendTxAndBroadcast(trx)
 }
 
diff --git a/txpool/mock.go b/txpool/mock.go
index cc63a1f62..5b5fa5ea6 100644
--- a/txpool/mock.go
+++ b/txpool/mock.go
@@ -15,7 +15,8 @@ var _ TxPool = &MockTxPool{}
 
 // MockTxPool is a testing mock.
 type MockTxPool struct {
-	Txs []*tx.Tx
+	Txs         []*tx.Tx
+	AppendError error
 }
 
 func MockingTxPool() *MockTxPool {
@@ -59,13 +60,13 @@ func (*MockTxPool) String() string {
 func (m *MockTxPool) AppendTx(trx *tx.Tx) error {
 	m.Txs = append(m.Txs, trx)
 
-	return nil
+	return m.AppendError
 }
 
 func (m *MockTxPool) AppendTxAndBroadcast(trx *tx.Tx) error {
 	m.Txs = append(m.Txs, trx)
 
-	return nil
+	return m.AppendError
 }
 
 func (m *MockTxPool) RemoveTx(id hash.Hash) {
diff --git a/wallet/wallet_test.go b/wallet/wallet_test.go
index 0e6fa8c59..c486820c0 100644
--- a/wallet/wallet_test.go
+++ b/wallet/wallet_test.go
@@ -11,7 +11,6 @@ import (
 	"github.com/pactus-project/pactus/types/account"
 	"github.com/pactus-project/pactus/types/tx/payload"
 	"github.com/pactus-project/pactus/util"
-	"github.com/pactus-project/pactus/util/errors"
 	"github.com/pactus-project/pactus/util/testsuite"
 	"github.com/pactus-project/pactus/wallet"
 	"github.com/pactus-project/pactus/www/grpc"
@@ -366,7 +365,7 @@ func TestMakeTransferTx(t *testing.T) {
 		td.Close()
 
 		_, err := td.wallet.MakeTransferTx(td.RandAccAddress().String(), receiverInfo.String(), amt)
-		assert.Equal(t, errors.ErrGeneric, errors.Code(err))
+		assert.Error(t, err)
 	})
 }
 
@@ -491,7 +490,7 @@ func TestMakeBondTx(t *testing.T) {
 		td.Close()
 
 		_, err := td.wallet.MakeBondTx(td.RandAccAddress().String(), receiver.Address().String(), "", amt)
-		assert.Equal(t, errors.ErrGeneric, errors.Code(err))
+		assert.Error(t, err)
 	})
 }
 
@@ -535,7 +534,7 @@ func TestMakeUnbondTx(t *testing.T) {
 		td.Close()
 
 		_, err := td.wallet.MakeUnbondTx(td.RandAccAddress().String())
-		assert.Equal(t, errors.ErrGeneric, errors.Code(err))
+		assert.Error(t, err)
 	})
 }
 
@@ -585,7 +584,7 @@ func TestMakeWithdrawTx(t *testing.T) {
 		td.Close()
 
 		_, err := td.wallet.MakeWithdrawTx(td.RandAccAddress().String(), receiverInfo.Address, amt)
-		assert.Equal(t, errors.ErrGeneric, errors.Code(err))
+		assert.Error(t, err)
 	})
 }
 
diff --git a/www/grpc/transaction_test.go b/www/grpc/transaction_test.go
index 7a3a9dd08..7cf827f35 100644
--- a/www/grpc/transaction_test.go
+++ b/www/grpc/transaction_test.go
@@ -3,6 +3,7 @@ package grpc
 import (
 	"context"
 	"encoding/hex"
+	"fmt"
 	"testing"
 
 	"github.com/pactus-project/pactus/types/amount"
@@ -111,7 +112,8 @@ func TestSendRawTransaction(t *testing.T) {
 		assert.NoError(t, err)
 		assert.NotNil(t, res)
 	})
-	t.Run("Should fail, Not Broadcasted", func(t *testing.T) {
+	t.Run("Should fail and not broadcast", func(t *testing.T) {
+		td.mockState.TestPool.AppendError = fmt.Errorf("some error")
 		res, err := client.BroadcastTransaction(context.Background(),
 			&pactus.BroadcastTransactionRequest{SignedRawTransaction: hex.EncodeToString(data)})
 		assert.Error(t, err)