diff --git a/backend/magic_plan/__init__.py b/backend/magic_plan/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/backend/magic_plan/magic_plan_trigger_request.py b/backend/magic_plan/magic_plan_trigger_request.py
new file mode 100644
index 00000000..bb0151e4
--- /dev/null
+++ b/backend/magic_plan/magic_plan_trigger_request.py
@@ -0,0 +1,10 @@
+from typing import Optional
+
+from pydantic import BaseModel, ConfigDict
+
+
+class MagicPlanTriggerRequest(BaseModel):
+    model_config = ConfigDict(extra="ignore")
+
+    address: str
+    uprn: Optional[str] = None
diff --git a/backend/magic_plan/tests/__init__.py b/backend/magic_plan/tests/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/backend/magic_plan/tests/test_magic_plan_trigger_request.py b/backend/magic_plan/tests/test_magic_plan_trigger_request.py
new file mode 100644
index 00000000..46a20a37
--- /dev/null
+++ b/backend/magic_plan/tests/test_magic_plan_trigger_request.py
@@ -0,0 +1,40 @@
+import pytest
+from pydantic import ValidationError
+
+from backend.magic_plan.magic_plan_trigger_request import MagicPlanTriggerRequest
+
+
+def test_valid_payload_with_address_only() -> None:
+    # Arrange
+    payload = {"address": "123 High St London SW1A 1AA"}
+    # Act
+    req = MagicPlanTriggerRequest.model_validate(payload)
+    # Assert
+    assert req.address == "123 High St London SW1A 1AA"
+    assert req.uprn is None
+
+
+def test_valid_payload_with_uprn() -> None:
+    # Arrange
+    payload = {"address": "123 High St London SW1A 1AA", "uprn": "100023336956"}
+    # Act
+    req = MagicPlanTriggerRequest.model_validate(payload)
+    # Assert
+    assert req.uprn == "100023336956"
+
+
+def test_missing_address_raises() -> None:
+    # Arrange
+    payload = {"uprn": "100023336956"}
+    # Act / Assert
+    with pytest.raises(ValidationError):
+        MagicPlanTriggerRequest.model_validate(payload)
+
+
+def test_extra_fields_ignored() -> None:
+    # Arrange
+    payload = {"address": "123 High St London SW1A 1AA", "unknown_field": "whatever"}
+    # Act
+    req = MagicPlanTriggerRequest.model_validate(payload)
+    # Assert
+    assert req.address == "123 High St London SW1A 1AA"