diff --git a/zetaclient/chains/base/amount.go b/zetaclient/chains/base/amount.go
new file mode 100644
index 0000000000..e9221d80b8
--- /dev/null
+++ b/zetaclient/chains/base/amount.go
@@ -0,0 +1,17 @@
+package base
+
+import (
+	cosmoserrors "cosmossdk.io/errors"
+	sdkmath "cosmossdk.io/math"
+
+	cctypes "github.com/zeta-chain/node/x/crosschain/types"
+)
+
+// OutboundAmountUint64 validates an amount can fit into uint64 and returns it.
+func OutboundAmountUint64(amount sdkmath.Uint) (uint64, error) {
+	if amount.BigInt().BitLen() > 64 {
+		return 0, cosmoserrors.Wrap(cctypes.ErrInvalidWithdrawalAmount, "amount exceeds uint64 range")
+	}
+
+	return amount.Uint64(), nil
+}
diff --git a/zetaclient/chains/base/amount_test.go b/zetaclient/chains/base/amount_test.go
new file mode 100644
index 0000000000..a61d33e905
--- /dev/null
+++ b/zetaclient/chains/base/amount_test.go
@@ -0,0 +1,27 @@
+package base
+
+import (
+	"math/big"
+	"testing"
+
+	sdkmath "cosmossdk.io/math"
+	"github.com/stretchr/testify/require"
+
+	cctypes "github.com/zeta-chain/node/x/crosschain/types"
+)
+
+func TestOutboundAmountUint64(t *testing.T) {
+	t.Run("returns amount within uint64 range", func(t *testing.T) {
+		maxUint64 := ^uint64(0)
+		amount, err := OutboundAmountUint64(sdkmath.NewUint(maxUint64))
+		require.NoError(t, err)
+		require.Equal(t, maxUint64, amount)
+	})
+
+	t.Run("fails if amount exceeds uint64 range", func(t *testing.T) {
+		amount := sdkmath.NewUintFromBigInt(new(big.Int).Lsh(big.NewInt(1), 64))
+
+		_, err := OutboundAmountUint64(amount)
+		require.ErrorIs(t, err, cctypes.ErrInvalidWithdrawalAmount)
+	})
+}
diff --git a/zetaclient/chains/solana/signer/execute.go b/zetaclient/chains/solana/signer/execute.go
index d2a6db12aa..18294eda60 100644
--- a/zetaclient/chains/solana/signer/execute.go
+++ b/zetaclient/chains/solana/signer/execute.go
@@ -17,6 +17,7 @@ import (
 	"github.com/zeta-chain/node/pkg/chains"
 	contracts "github.com/zeta-chain/node/pkg/contracts/solana"
 	"github.com/zeta-chain/node/x/crosschain/types"
+	"github.com/zeta-chain/node/zetaclient/chains/base"
 	zctx "github.com/zeta-chain/node/zetaclient/context"
 )
 
@@ -156,11 +157,15 @@ func (signer *Signer) createMsgExecute(
 	// #nosec G115 always positive
 	chainID := uint64(signer.Chain().ChainId)
 	nonce := params.TssNonce
-	amount := params.Amount.Uint64()
+	amount := uint64(0)
 
 	// zero out the amount if cancelTx is set. It's legal to withdraw 0 lamports through the gateway.
-	if cancelTx {
-		amount = 0
+	if !cancelTx {
+		var err error
+		amount, err = base.OutboundAmountUint64(params.Amount)
+		if err != nil {
+			return nil, nil, err
+		}
 	}
 
 	// prepare data for msg execute
diff --git a/zetaclient/chains/solana/signer/execute_spl.go b/zetaclient/chains/solana/signer/execute_spl.go
index 563a42a768..98c0838091 100644
--- a/zetaclient/chains/solana/signer/execute_spl.go
+++ b/zetaclient/chains/solana/signer/execute_spl.go
@@ -12,6 +12,7 @@ import (
 	"github.com/zeta-chain/node/pkg/chains"
 	contracts "github.com/zeta-chain/node/pkg/contracts/solana"
 	"github.com/zeta-chain/node/x/crosschain/types"
+	"github.com/zeta-chain/node/zetaclient/chains/base"
 )
 
 // prepareExecuteSPLTx prepares execute spl outbound
@@ -63,11 +64,15 @@ func (signer *Signer) createMsgExecuteSPL(
 	// #nosec G115 always positive
 	chainID := uint64(signer.Chain().ChainId)
 	nonce := params.TssNonce
-	amount := params.Amount.Uint64()
+	amount := uint64(0)
 
 	// zero out the amount if cancelTx is set. It's legal to withdraw 0 spl through the gateway.
-	if cancelTx {
-		amount = 0
+	if !cancelTx {
+		var err error
+		amount, err = base.OutboundAmountUint64(params.Amount)
+		if err != nil {
+			return nil, nil, err
+		}
 	}
 
 	// get mint details to get decimals
diff --git a/zetaclient/chains/solana/signer/increment_nonce.go b/zetaclient/chains/solana/signer/increment_nonce.go
index 5520e043cc..9ebb400ce2 100644
--- a/zetaclient/chains/solana/signer/increment_nonce.go
+++ b/zetaclient/chains/solana/signer/increment_nonce.go
@@ -11,6 +11,7 @@ import (
 	"github.com/zeta-chain/node/pkg/coin"
 	contracts "github.com/zeta-chain/node/pkg/contracts/solana"
 	"github.com/zeta-chain/node/x/crosschain/types"
+	"github.com/zeta-chain/node/zetaclient/chains/base"
 	"github.com/zeta-chain/node/zetaclient/compliance"
 )
 
@@ -70,11 +71,15 @@ func (signer *Signer) createAndSignMsgIncrementNonce(
 	// #nosec G115 always positive
 	chainID := uint64(signer.Chain().ChainId)
 	nonce := params.TssNonce
-	amount := params.Amount.Uint64()
+	amount := uint64(0)
 
 	// zero out the amount if cancelTx is set. It's legal to withdraw 0 lamports through the gateway.
-	if cancelTx {
-		amount = 0
+	if !cancelTx {
+		var err error
+		amount, err = base.OutboundAmountUint64(params.Amount)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	// prepare increment_nonce msg and compute hash
diff --git a/zetaclient/chains/solana/signer/withdraw.go b/zetaclient/chains/solana/signer/withdraw.go
index 40296e728b..a8c5f29fea 100644
--- a/zetaclient/chains/solana/signer/withdraw.go
+++ b/zetaclient/chains/solana/signer/withdraw.go
@@ -11,6 +11,7 @@ import (
 	"github.com/zeta-chain/node/pkg/chains"
 	contracts "github.com/zeta-chain/node/pkg/contracts/solana"
 	"github.com/zeta-chain/node/x/crosschain/types"
+	"github.com/zeta-chain/node/zetaclient/chains/base"
 )
 
 // prepareWithdrawTx prepares withdraw outbound
@@ -53,11 +54,15 @@ func (signer *Signer) createMsgWithdraw(
 	// #nosec G115 always positive
 	chainID := uint64(signer.Chain().ChainId)
 	nonce := params.TssNonce
-	amount := params.Amount.Uint64()
+	amount := uint64(0)
 
 	// zero out the amount if cancelTx is set. It's legal to withdraw 0 lamports through the gateway.
-	if cancelTx {
-		amount = 0
+	if !cancelTx {
+		var err error
+		amount, err = base.OutboundAmountUint64(params.Amount)
+		if err != nil {
+			return nil, nil, err
+		}
 	}
 
 	// check receiver address
diff --git a/zetaclient/chains/solana/signer/withdraw_spl.go b/zetaclient/chains/solana/signer/withdraw_spl.go
index 5d07bc807c..bbfa862fc0 100644
--- a/zetaclient/chains/solana/signer/withdraw_spl.go
+++ b/zetaclient/chains/solana/signer/withdraw_spl.go
@@ -12,6 +12,7 @@ import (
 	"github.com/zeta-chain/node/pkg/chains"
 	contracts "github.com/zeta-chain/node/pkg/contracts/solana"
 	"github.com/zeta-chain/node/x/crosschain/types"
+	"github.com/zeta-chain/node/zetaclient/chains/base"
 )
 
 // prepareWithdrawSPLTx prepares withdraw spl outbound
@@ -60,11 +61,15 @@ func (signer *Signer) createMsgWithdrawSPL(
 	// #nosec G115 always positive
 	chainID := uint64(signer.Chain().ChainId)
 	nonce := params.TssNonce
-	amount := params.Amount.Uint64()
+	amount := uint64(0)
 
 	// zero out the amount if cancelTx is set. It's legal to withdraw 0 spl through the gateway.
-	if cancelTx {
-		amount = 0
+	if !cancelTx {
+		var err error
+		amount, err = base.OutboundAmountUint64(params.Amount)
+		if err != nil {
+			return nil, nil, err
+		}
 	}
 
 	// get mint details to get decimals
diff --git a/zetaclient/chains/sui/signer/signer_tx.go b/zetaclient/chains/sui/signer/signer_tx.go
index ea130f8219..aa8ad94a39 100644
--- a/zetaclient/chains/sui/signer/signer_tx.go
+++ b/zetaclient/chains/sui/signer/signer_tx.go
@@ -15,6 +15,7 @@ import (
 	"github.com/zeta-chain/node/pkg/coin"
 	zetasui "github.com/zeta-chain/node/pkg/contracts/sui"
 	cctypes "github.com/zeta-chain/node/x/crosschain/types"
+	"github.com/zeta-chain/node/zetaclient/chains/base"
 	"github.com/zeta-chain/node/zetaclient/chains/sui/client"
 	"github.com/zeta-chain/node/zetaclient/logs"
 )
@@ -159,6 +160,10 @@ func (s *Signer) buildWithdrawAndCallTx(
 	payloadHex string,
 ) (models.TxnMetaData, error) {
 	params := cctx.GetCurrentOutboundParam()
+	amount, err := base.OutboundAmountUint64(params.Amount)
+	if err != nil {
+		return models.TxnMetaData{}, err
+	}
 
 	// decode and parse the payload into object IDs and on_call arguments
 	payloadBytes, err := hex.DecodeString(payloadHex)
@@ -181,7 +186,7 @@ func (s *Signer) buildWithdrawAndCallTx(
 	args := withdrawAndCallPTBArgs{
 		withdrawAndCallObjRefs: wacRefs,
 		coinType:               coinType,
-		amount:                 params.Amount.Uint64(),
+		amount:                 amount,
 		nonce:                  params.TssNonce,
 		gasBudget:              gasBudget,
 		sender:                 ethcommon.HexToAddress(cctx.InboundParams.Sender).Hex(),