diff --git a/app/services/pal24_service.py b/app/services/pal24_service.py
index fa9ef8e8..26b7e799 100644
--- a/app/services/pal24_service.py
+++ b/app/services/pal24_service.py
@@ -5,8 +5,7 @@ from __future__ import annotations
 import logging
 from datetime import datetime, timedelta
 from decimal import Decimal
-import json
-from typing import Any, Dict, Optional, Union
+from typing import Any, Dict, Optional
 
 from app.config import settings
 from app.external.pal24_client import Pal24Client, Pal24APIError
@@ -36,7 +35,7 @@ class Pal24Service:
         order_id: str,
         description: str,
         ttl_seconds: Optional[int] = None,
-        custom_payload: Optional[Union[Dict[str, Any], str]] = None,
+        custom_payload: Optional[Dict[str, Any]] = None,
         payer_email: Optional[str] = None,
         payment_method: Optional[str] = None,
     ) -> Dict[str, Any]:
@@ -44,22 +43,10 @@ class Pal24Service:
             raise Pal24APIError("Pal24 service is not configured")
 
         amount_decimal = Pal24Client.normalize_amount(amount_kopeks)
-        extra_payload: Dict[str, Any] = {"ttl": ttl_seconds}
-
-        if custom_payload is not None:
-            if isinstance(custom_payload, str):
-                extra_payload["custom"] = custom_payload
-            else:
-                try:
-                    extra_payload["custom"] = json.dumps(
-                        custom_payload,
-                        ensure_ascii=False,
-                        separators=(",", ":"),
-                    )
-                except (TypeError, ValueError) as error:
-                    raise Pal24APIError(
-                        "Unable to serialize Pal24 custom payload to JSON"
-                    ) from error
+        extra_payload: Dict[str, Any] = {
+            "custom": custom_payload or {},
+            "ttl": ttl_seconds,
+        }
 
         if payer_email:
             extra_payload["payer_email"] = payer_email
diff --git a/tests/services/test_pal24_service_adapter.py b/tests/services/test_pal24_service_adapter.py
index d1fd744a..f371039a 100644
--- a/tests/services/test_pal24_service_adapter.py
+++ b/tests/services/test_pal24_service_adapter.py
@@ -4,7 +4,6 @@ from __future__ import annotations
 
 from datetime import datetime, timedelta
 from decimal import Decimal
-import json
 from pathlib import Path
 from typing import Any, Dict, Optional
 import sys
@@ -78,7 +77,6 @@ async def test_create_bill_success(monkeypatch: pytest.MonkeyPatch) -> None:
     assert client.calls and client.calls[0]["amount"] == Decimal("500.00")
     assert client.calls[0]["shop_id"] == "shop42"
     assert client.calls[0]["description"] == "Пополнение"
-    assert client.calls[0]["custom"] == json.dumps({"extra": "value"}, ensure_ascii=False, separators=(",", ":"))
 
 
 @pytest.mark.anyio("asyncio")