diff --git a/app/Traits/Order/WithMember.php b/app/Traits/Order/WithMember.php
index cb638e1..ea6ed7e 100644
--- a/app/Traits/Order/WithMember.php
+++ b/app/Traits/Order/WithMember.php
@@ -43,7 +43,16 @@ public function updatedFormVoucherId(?string $voucherId = null): void
 
         $subtotal = $this->getSubtotal();
 
-        $this->voucherDiscount = $this->calculateDiscount($subtotal, $voucher->id);
+        $voucherDiscountResult = $this->calculateDiscount($subtotal, $voucher->id);
+
+        if (is_array($voucherDiscountResult)) {
+            // Error case - reset voucher discount and show error
+            $this->voucherDiscount = 0;
+            $this->form->voucher_id = ''; // Reset voucher selection
+            $this->toast($voucherDiscountResult['message'], 'Error', 'danger');
+        } else {
+            $this->voucherDiscount = $voucherDiscountResult;
+        }
 
         $this->total = $this->getTotal();
     }