diff --git a/src/broker/overseas.py b/src/broker/overseas.py
index 3d37acb..fe9d448 100644
--- a/src/broker/overseas.py
+++ b/src/broker/overseas.py
@@ -230,7 +230,9 @@ class OverseasBroker:
         session = self._broker._get_session()
 
         # Virtual trading TR_IDs for overseas orders
-        tr_id = "VTTT1002U" if order_type == "BUY" else "VTTT1006U"
+        # Source: 한국투자증권 오픈API 전체문서 (20260221) — '해외주식 주문' 시트
+        # VTTT1002U: 모의투자 미국 매수, VTTT1001U: 모의투자 미국 매도
+        tr_id = "VTTT1002U" if order_type == "BUY" else "VTTT1001U"
 
         body = {
             "CANO": self._broker._account_no,
diff --git a/tests/test_overseas_broker.py b/tests/test_overseas_broker.py
index 620b98d..08f7fb5 100644
--- a/tests/test_overseas_broker.py
+++ b/tests/test_overseas_broker.py
@@ -414,7 +414,7 @@ class TestSendOverseasOrder:
 
     @pytest.mark.asyncio
     async def test_sell_limit_order(self, overseas_broker: OverseasBroker) -> None:
-        """Limit sell order should use VTTT1006U and ORD_DVSN=00."""
+        """Limit sell order should use VTTT1001U and ORD_DVSN=00."""
         mock_resp = AsyncMock()
         mock_resp.status = 200
         mock_resp.json = AsyncMock(return_value={"rt_cd": "0"})
@@ -428,7 +428,7 @@ class TestSendOverseasOrder:
         result = await overseas_broker.send_overseas_order("NYSE", "MSFT", "SELL", 5, price=350.0)
         assert result["rt_cd"] == "0"
 
-        overseas_broker._broker._auth_headers.assert_called_with("VTTT1006U")
+        overseas_broker._broker._auth_headers.assert_called_with("VTTT1001U")
 
         call_args = mock_session.post.call_args
         body = call_args[1]["json"]