diff --git a/x/auth/middleware/basic_test.go b/x/auth/middleware/basic_test.go
index 1c44e292eb93..7bc583ed8d75 100644
--- a/x/auth/middleware/basic_test.go
+++ b/x/auth/middleware/basic_test.go
@@ -33,22 +33,37 @@ func (s *MWTestSuite) TestValidateBasic() {
 	invalidTx, _, err := s.createTestTx(txBuilder, privs, accNums, accSeqs, ctx.ChainID())
 	s.Require().NoError(err)
 
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: invalidTx})
 	s.Require().NotNil(err, "Did not error on invalid tx")
 
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: invalidTx})
+	s.Require().NotNil(err, "Did not error on invalid tx")
+
 	privs, accNums, accSeqs = []cryptotypes.PrivKey{priv1}, []uint64{0}, []uint64{0}
 	validTx, _, err := s.createTestTx(txBuilder, privs, accNums, accSeqs, ctx.ChainID())
 	s.Require().NoError(err)
 
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: validTx})
 	s.Require().Nil(err, "ValidateBasicMiddleware returned error on valid tx. err: %v", err)
 
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: validTx})
+	s.Require().Nil(err, "ValidateBasicMiddleware returned error on valid tx. err: %v", err)
+
 	// test middleware skips on recheck
 	ctx = ctx.WithIsReCheckTx(true)
 
 	// middleware should skip processing invalidTx on recheck and thus return nil-error
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: invalidTx})
 	s.Require().Nil(err, "ValidateBasicMiddleware ran on ReCheck")
+
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: invalidTx})
+	s.Require().Nil(err, "ValidateBasicMiddleware ran on ReCheck")
 }
 
 func (s *MWTestSuite) TestValidateMemo() {
@@ -73,8 +88,12 @@ func (s *MWTestSuite) TestValidateMemo() {
 	s.Require().NoError(err)
 
 	// require that long memos get rejected
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: invalidTx})
+	s.Require().NotNil(err, "Did not error on tx with high memo")
 
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: invalidTx})
 	s.Require().NotNil(err, "Did not error on tx with high memo")
 
 	txBuilder.SetMemo(strings.Repeat("01234567890", 10))
@@ -82,8 +101,13 @@ func (s *MWTestSuite) TestValidateMemo() {
 	s.Require().NoError(err)
 
 	// require small memos pass ValidateMemo middleware
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: validTx})
 	s.Require().Nil(err, "ValidateBasicMiddleware returned error on valid tx. err: %v", err)
+
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: validTx})
+	s.Require().Nil(err, "ValidateBasicMiddleware returned error on valid tx. err: %v", err)
 }
 
 func (s *MWTestSuite) TestConsumeGasForTxSize() {
@@ -214,8 +238,15 @@ func (s *MWTestSuite) TestTxHeightTimeoutMiddleware() {
 			s.Require().NoError(err)
 
 			ctx := ctx.WithBlockHeight(tc.height)
+
+			// DeliverTx
+			_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
+			s.Require().Equal(tc.expectErr, err != nil, err)
+
+			// SimulateTx
 			_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
 			s.Require().Equal(tc.expectErr, err != nil, err)
+
 		})
 	}
 }
diff --git a/x/auth/middleware/fee_test.go b/x/auth/middleware/fee_test.go
index 7c1f54463fff..9899e2aa63c3 100644
--- a/x/auth/middleware/fee_test.go
+++ b/x/auth/middleware/fee_test.go
@@ -100,15 +100,27 @@ func (s *MWTestSuite) TestDeductFees() {
 	err = testutil.FundAccount(s.app.BankKeeper, ctx, addr1, coins)
 	s.Require().NoError(err)
 
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
-	s.Require().NotNil(err, "Tx did not error when fee payer had insufficient funds")
+	s.Require().NotNil(err, "Tx errored when fee payer had insufficient funds")
+
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
+	s.Require().NotNil(err, "Tx errored when fee payer had insufficient funds")
 
 	// Set account with sufficient funds
 	s.app.AccountKeeper.SetAccount(ctx, acc)
 	err = testutil.FundAccount(s.app.BankKeeper, ctx, addr1, sdk.NewCoins(sdk.NewCoin("atom", sdk.NewInt(200))))
 	s.Require().NoError(err)
 
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
+	s.Require().Nil(err, "Tx did not error after account has been set with sufficient funds")
+
+	err = testutil.FundAccount(s.app.BankKeeper, ctx, addr1, sdk.NewCoins(sdk.NewCoin("atom", sdk.NewInt(200))))
+	s.Require().NoError(err)
 
-	s.Require().Nil(err, "Tx errored after account has been set with sufficient funds")
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
+	s.Require().Nil(err, "Tx did not error after account has been set with sufficient funds")
 }
diff --git a/x/auth/middleware/gas_test.go b/x/auth/middleware/gas_test.go
index 78685fa6c766..480077762149 100644
--- a/x/auth/middleware/gas_test.go
+++ b/x/auth/middleware/gas_test.go
@@ -65,10 +65,13 @@ func (s *MWTestSuite) TestSetup() {
 	for _, tc := range testcases {
 		s.Run(tc.name, func() {
 			res, _, err := txHandler.CheckTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: tc.tx}, tx.RequestCheckTx{})
+			_, simErr := txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: tc.tx})
 			if tc.expErr {
 				s.Require().EqualError(err, tc.errorStr)
+				s.Require().EqualError(simErr, tc.errorStr)
 			} else {
 				s.Require().Nil(err, "SetUpContextMiddleware returned error")
+				s.Require().Nil(simErr, "SetUpContextMiddleware returned error")
 				s.Require().Equal(tc.expGasLimit, uint64(res.GasWanted))
 			}
 		})
diff --git a/x/auth/middleware/run_msgs_test.go b/x/auth/middleware/run_msgs_test.go
index 6278d5c023d2..143a21975380 100644
--- a/x/auth/middleware/run_msgs_test.go
+++ b/x/auth/middleware/run_msgs_test.go
@@ -28,8 +28,13 @@ func (s *MWTestSuite) TestRunMsgs() {
 	txBytes, err := s.clientCtx.TxConfig.TxEncoder()(testTx)
 	s.Require().NoError(err)
 
+	// DeliverTx
 	res, err := txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx, TxBytes: txBytes})
 	s.Require().NoError(err)
 	s.Require().Len(res.MsgResponses, 1)
 	s.Require().Equal(fmt.Sprintf("/%s", proto.MessageName(&testdata.MsgCreateDogResponse{})), res.MsgResponses[0].TypeUrl)
+
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx, TxBytes: txBytes})
+	s.Require().NoError(err)
 }
diff --git a/x/auth/middleware/sigverify_test.go b/x/auth/middleware/sigverify_test.go
index a0c68062a968..fd4fc5622041 100644
--- a/x/auth/middleware/sigverify_test.go
+++ b/x/auth/middleware/sigverify_test.go
@@ -55,6 +55,7 @@ func (s *MWTestSuite) TestSetPubKey() {
 	testTx, _, err := s.createTestTx(txBuilder, privs, accNums, accSeqs, ctx.ChainID())
 	require.NoError(err)
 
+	// DeliverTx
 	_, err = txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
 	require.NoError(err)
 
@@ -65,6 +66,10 @@ func (s *MWTestSuite) TestSetPubKey() {
 		require.True(pubs[i].Equals(pk),
 			"Wrong Pubkey retrieved from AccountKeeper, idx=%d\nexpected=%s\n     got=%s", i, pubs[i], pk)
 	}
+
+	// SimulateTx
+	_, err = txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tx.Request{Tx: testTx})
+	require.NoError(err)
 }
 
 func (s *MWTestSuite) TestConsumeSignatureVerificationGas() {
diff --git a/x/auth/middleware/tx_test.go b/x/auth/middleware/tx_test.go
index 8624aadbfea2..9e4ce65ed648 100644
--- a/x/auth/middleware/tx_test.go
+++ b/x/auth/middleware/tx_test.go
@@ -46,11 +46,18 @@ func (s *MWTestSuite) TestTxDecoderMiddleware() {
 				txReqChecker,
 				middleware.NewTxDecoderMiddleware(s.clientCtx.TxConfig.TxDecoder()),
 			)
+
+			// DeliverTx
 			_, err := txHandler.DeliverTx(sdk.WrapSDKContext(ctx), tc.req)
+
+			// SimulateTx
+			_, simErr := txHandler.SimulateTx(sdk.WrapSDKContext(ctx), tc.req)
 			if tc.expErr {
 				require.Error(err)
+				require.Error(simErr)
 			} else {
 				require.NoError(err)
+				require.NoError(simErr)
 			}
 		})
 	}