diff --git a/WebToPay.php b/WebToPay.php
index d53b8ae..9995155 100644
--- a/WebToPay.php
+++ b/WebToPay.php
@@ -240,18 +240,13 @@ public static function smsAnswer(array $userData): void
     /**
      * Gets available payment methods for project. Gets methods min and max amounts in specified currency.
      *
-     * @param integer $projectId
-     * @param float   $amount
-     * @param string  $currency
-     *
-     * @return WebToPay_PaymentMethodList
-     *
      * @throws WebToPayException
+     * @throws WebToPay_Exception_Configuration
      */
     public static function getPaymentMethodList(
         int $projectId,
-        float $amount,
-        string $currency = 'EUR'
+        ?float $amount,
+        ?string $currency = 'EUR'
     ): WebToPay_PaymentMethodList {
         $factory = new WebToPay_Factory(['projectId' => $projectId]);
 
@@ -261,10 +256,6 @@ public static function getPaymentMethodList(
     /**
      * Logs to file. Just skips logging if file is not writeable
      *
-     * @param string $type
-     * @param string $msg
-     * @param string $logfile
-     *
      * @deprecated
      * @codeCoverageIgnore
      */
@@ -1550,7 +1541,7 @@ public function __construct(
      *
      * @throws WebToPayException
      */
-    public function getPaymentMethodList(float $amount, string $currency): WebToPay_PaymentMethodList
+    public function getPaymentMethodList(?float $amount, ?string $currency): WebToPay_PaymentMethodList
     {
         if (!isset($this->methodListCache[$currency])) {
             $xmlAsString = $this->webClient->get(
@@ -1865,7 +1856,7 @@ public function buildForRequest(array $request): string
     /**
      * Builds a complete URL for payment list API
      */
-    public function buildForPaymentsMethodList(int $projectId, string $amount, string $currency): string
+    public function buildForPaymentsMethodList(int $projectId, ?string $amount, ?string $currency): string
     {
         $route = $this->environmentSettings['paymentMethodList'];
 
diff --git a/src/WebToPay.php b/src/WebToPay.php
index cbb3674..42a5b0d 100644
--- a/src/WebToPay.php
+++ b/src/WebToPay.php
@@ -236,18 +236,13 @@ public static function smsAnswer(array $userData): void
     /**
      * Gets available payment methods for project. Gets methods min and max amounts in specified currency.
      *
-     * @param integer $projectId
-     * @param float   $amount
-     * @param string  $currency
-     *
-     * @return WebToPay_PaymentMethodList
-     *
      * @throws WebToPayException
+     * @throws WebToPay_Exception_Configuration
      */
     public static function getPaymentMethodList(
         int $projectId,
-        float $amount,
-        string $currency = 'EUR'
+        ?float $amount,
+        ?string $currency = 'EUR'
     ): WebToPay_PaymentMethodList {
         $factory = new WebToPay_Factory(['projectId' => $projectId]);
 
@@ -257,10 +252,6 @@ public static function getPaymentMethodList(
     /**
      * Logs to file. Just skips logging if file is not writeable
      *
-     * @param string $type
-     * @param string $msg
-     * @param string $logfile
-     *
      * @deprecated
      * @codeCoverageIgnore
      */
diff --git a/src/WebToPay/PaymentMethodListProvider.php b/src/WebToPay/PaymentMethodListProvider.php
index 5977e22..5287c1e 100644
--- a/src/WebToPay/PaymentMethodListProvider.php
+++ b/src/WebToPay/PaymentMethodListProvider.php
@@ -48,7 +48,7 @@ public function __construct(
      *
      * @throws WebToPayException
      */
-    public function getPaymentMethodList(float $amount, string $currency): WebToPay_PaymentMethodList
+    public function getPaymentMethodList(?float $amount, ?string $currency): WebToPay_PaymentMethodList
     {
         if (!isset($this->methodListCache[$currency])) {
             $xmlAsString = $this->webClient->get(
diff --git a/src/WebToPay/UrlBuilder.php b/src/WebToPay/UrlBuilder.php
index 603bc04..c2ec5a3 100644
--- a/src/WebToPay/UrlBuilder.php
+++ b/src/WebToPay/UrlBuilder.php
@@ -54,7 +54,7 @@ public function buildForRequest(array $request): string
     /**
      * Builds a complete URL for payment list API
      */
-    public function buildForPaymentsMethodList(int $projectId, string $amount, string $currency): string
+    public function buildForPaymentsMethodList(int $projectId, ?string $amount, ?string $currency): string
     {
         $route = $this->environmentSettings['paymentMethodList'];
 
diff --git a/tests/StaticMethods/WebToPayTest.php b/tests/StaticMethods/WebToPayTest.php
index b91d903..c51eb81 100644
--- a/tests/StaticMethods/WebToPayTest.php
+++ b/tests/StaticMethods/WebToPayTest.php
@@ -141,16 +141,28 @@ public function testValidateAndParseData(): void
         WebToPay::validateAndParseData($request, 123, 'password');
     }
 
+    public function getDataForTestingGetPaymentMethodList(): iterable
+    {
+        yield 'amount is null' => [
+            'amount' => null,
+            'currency' => 'EUR',
+        ];
+
+        yield 'currency is null' => [
+            'amount' => 1000,
+            'currency' => null,
+        ];
+    }
+
     /**
+     * @dataProvider getDataForTestingGetPaymentMethodList
+     *
      * @throws WebToPayException
      * @throws WebToPay_Exception_Callback
      * @throws WebToPay_Exception_Configuration
      */
-    public function testGetPaymentMethodList(): void
+    public function testGetPaymentMethodList(?int $amount, ?string $currency): void
     {
-        $amount = 1000;
-        $currency = 'EUR';
-
         $paymentMethodListProviderMock = $this->createMock(WebToPay_PaymentMethodListProvider::class);
         $paymentMethodListProviderMock->expects($this->once())
             ->method('getPaymentMethodList')
diff --git a/tests/WebToPay/UrlBuilderTest.php b/tests/WebToPay/UrlBuilderTest.php
index bd5934b..d480ad7 100644
--- a/tests/WebToPay/UrlBuilderTest.php
+++ b/tests/WebToPay/UrlBuilderTest.php
@@ -37,13 +37,34 @@ public function testBuildForRequest()
         );
     }
 
-    public function testBuildForPaymentsMethodList()
+    public function getDataForTestingBuildForPaymentsMethodList(): iterable
     {
-        $url = $this->urlBuilder->buildForPaymentsMethodList(1, '1.00', 'EUR');
+        yield 'amount is not null; currency is not null' => [
+            'amount' => '1.00',
+            'currency' => 'EUR',
+            'expectedUrl' => 'https://sandbox.paysera.com/new/api/paymentMethods/1/currency:EUR/amount:1.00',
+        ];
 
-        $this->assertEquals(
-            'https://sandbox.paysera.com/new/api/paymentMethods/1/currency:EUR/amount:1.00',
-            $url
-        );
+        yield 'amount is null; currency is not null' => [
+            'amount' => null,
+            'currency' => 'EUR',
+            'expectedUrl' => 'https://sandbox.paysera.com/new/api/paymentMethods/1/currency:EUR/amount:',
+        ];
+
+        yield 'amount is not null; currency is null' => [
+            'amount' => '1.00',
+            'currency' => null,
+            'expectedUrl' => 'https://sandbox.paysera.com/new/api/paymentMethods/1/currency:/amount:1.00',
+        ];
+    }
+
+    /**
+     * @dataProvider getDataForTestingBuildForPaymentsMethodList
+     */
+    public function testBuildForPaymentsMethodList(?string $amount, ?string $currency, string $expectedUrl)
+    {
+        $url = $this->urlBuilder->buildForPaymentsMethodList(1, $amount, $currency);
+
+        $this->assertEquals($expectedUrl, $url);
     }
 }