diff --git a/src/Model/Fields/Transaction/Currency.php b/src/Model/Fields/Transaction/Currency.php
new file mode 100644
index 0000000..e1c2b93
--- /dev/null
+++ b/src/Model/Fields/Transaction/Currency.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Tpay\OpenApi\Model\Fields\Transaction;
+
+use Tpay\OpenApi\Model\Fields\Field;
+
+/**
+ * @method getValue(): string
+ */
+class Currency extends Field
+{
+    protected $name = __CLASS__;
+    protected $type = self::STRING;
+    protected $maxLength = 3;
+    protected $minLength = 3;
+}
diff --git a/src/Model/Objects/RequestBody/Transaction.php b/src/Model/Objects/RequestBody/Transaction.php
index f9806fa..1dcbd4b 100644
--- a/src/Model/Objects/RequestBody/Transaction.php
+++ b/src/Model/Objects/RequestBody/Transaction.php
@@ -3,6 +3,7 @@
 namespace Tpay\OpenApi\Model\Objects\RequestBody;
 
 use Tpay\OpenApi\Model\Fields\Transaction\Amount;
+use Tpay\OpenApi\Model\Fields\Transaction\Currency;
 use Tpay\OpenApi\Model\Fields\Transaction\Description;
 use Tpay\OpenApi\Model\Fields\Transaction\HiddenDescription;
 use Tpay\OpenApi\Model\Fields\Transaction\Lang;
@@ -15,6 +16,7 @@ class Transaction extends Objects
 {
     const OBJECT_FIELDS = [
         'amount' => Amount::class,
+        'currency' => Currency::class,
         'description' => Description::class,
         'hiddenDescription' => HiddenDescription::class,
         'lang' => Lang::class,
@@ -27,6 +29,9 @@ class Transaction extends Objects
     /** @var Amount */
     public $amount;
 
+    /** @var Currency */
+    public $currency;
+
     /** @var Description */
     public $description;
 
diff --git a/src/Model/Objects/RequestBody/TransactionWithInstantRedirection.php b/src/Model/Objects/RequestBody/TransactionWithInstantRedirection.php
index 7b78395..d82ce7b 100644
--- a/src/Model/Objects/RequestBody/TransactionWithInstantRedirection.php
+++ b/src/Model/Objects/RequestBody/TransactionWithInstantRedirection.php
@@ -3,6 +3,7 @@
 namespace Tpay\OpenApi\Model\Objects\RequestBody;
 
 use Tpay\OpenApi\Model\Fields\Transaction\Amount;
+use Tpay\OpenApi\Model\Fields\Transaction\Currency;
 use Tpay\OpenApi\Model\Fields\Transaction\Description;
 use Tpay\OpenApi\Model\Fields\Transaction\HiddenDescription;
 use Tpay\OpenApi\Model\Fields\Transaction\Lang;
@@ -14,6 +15,7 @@ class TransactionWithInstantRedirection extends Objects
 {
     const OBJECT_FIELDS = [
         'amount' => Amount::class,
+        'currency' => Currency::class,
         'description' => Description::class,
         'hiddenDescription' => HiddenDescription::class,
         'lang' => Lang::class,
@@ -25,6 +27,9 @@ class TransactionWithInstantRedirection extends Objects
     /** @var Amount */
     public $amount;
 
+    /** @var Currency */
+    public $currency;
+
     /** @var Description */
     public $description;