diff --git a/src/Core/Gateway.php b/src/Core/Gateway.php
index b8d6f021..529385cc 100644
--- a/src/Core/Gateway.php
+++ b/src/Core/Gateway.php
@@ -324,6 +324,12 @@ public function redirect_via_html( Payment $payment ) {
 	 * @throws \Exception When payment action URL is empty.
 	 */
 	public function get_form_html( Payment $payment ) {
+		$action_url = $payment->get_action_url();
+
+		if ( empty( $action_url ) ) {
+			throw new \Exception( 'Action URL is empty, can not get form HTML.' );
+		}
+
 		$form_inner = $this->get_output_html( $payment );
 
 		$form_inner .= sprintf(
@@ -331,12 +337,6 @@ public function get_form_html( Payment $payment ) {
 			__( 'Pay', 'pronamic_ideal' )
 		);
 
-		$action_url = $payment->get_action_url();
-
-		if ( empty( $action_url ) ) {
-			throw new \Exception( 'Action URL is empty, can not get form HTML.' );
-		}
-
 		$html = sprintf(
 			'<form id="pronamic_ideal_form" name="pronamic_ideal_form" method="post" action="%s">%s</form>',
 			esc_attr( $action_url ),