diff --git a/tests/payments/payment_request_fields_serialization_test.py b/tests/payments/payment_request_fields_serialization_test.py
new file mode 100644
index 0000000..f1628f2
--- /dev/null
+++ b/tests/payments/payment_request_fields_serialization_test.py
@@ -0,0 +1,51 @@
+import json
+
+from checkout_sdk.json_serializer import JsonSerializer
+from checkout_sdk.payments.payments import AuthorizationType, PaymentPlan
+from checkout_sdk.payments.hosted.hosted_payments import HostedPaymentsSessionRequest
+from checkout_sdk.payments.links.payments_links import PaymentLinkRequest
+from checkout_sdk.payments.sessions.sessions import PaymentSessionsRequest
+
+
+def _serialize(obj):
+    return json.loads(json.dumps(obj, cls=JsonSerializer))
+
+
+def _payment_plan():
+    plan = PaymentPlan()
+    plan.days_between_payments = 30
+    plan.total_number_of_payments = 12
+    return plan
+
+
+class TestPaymentRequestFieldsSerialization:
+
+    def test_hosted_payments_request_serializes_authorization_type_and_payment_plan(self):
+        request = HostedPaymentsSessionRequest()
+        request.authorization_type = AuthorizationType.ESTIMATED
+        request.payment_plan = _payment_plan()
+
+        assert _serialize(request) == {
+            'authorization_type': 'Estimated',
+            'payment_plan': {'days_between_payments': 30, 'total_number_of_payments': 12},
+        }
+
+    def test_payment_link_request_serializes_authorization_type_and_payment_plan(self):
+        request = PaymentLinkRequest()
+        request.authorization_type = AuthorizationType.INCREMENTAL
+        request.payment_plan = _payment_plan()
+
+        assert _serialize(request) == {
+            'authorization_type': 'Incremental',
+            'payment_plan': {'days_between_payments': 30, 'total_number_of_payments': 12},
+        }
+
+    def test_payment_sessions_request_serializes_authorization_type_and_payment_plan(self):
+        request = PaymentSessionsRequest()
+        request.authorization_type = AuthorizationType.FINAL
+        request.payment_plan = _payment_plan()
+
+        assert _serialize(request) == {
+            'authorization_type': 'Final',
+            'payment_plan': {'days_between_payments': 30, 'total_number_of_payments': 12},
+        }