diff --git a/service/models/operations/calibrate.py b/service/models/operations/calibrate.py
index 073ecf8..8cb31be 100644
--- a/service/models/operations/calibrate.py
+++ b/service/models/operations/calibrate.py
@@ -45,7 +45,7 @@ class Calibrate(OperationRequest):
     model_config_id: str = Field(..., example="c1cd941a-047d-11ee-be56")
     dataset: Dataset = None
     timespan: Optional[Timespan] = None
-    policy_intervention_id: str = Field(..., example="ba8da8d4-047d-11ee-be56")
+    policy_intervention_id: str = Field(None, example="ba8da8d4-047d-11ee-be56")
     extra: CalibrateExtra = Field(
         None,
         description="optional extra system specific arguments for advanced use cases",
diff --git a/service/models/operations/simulate.py b/service/models/operations/simulate.py
index d6ea3e8..a162e9d 100644
--- a/service/models/operations/simulate.py
+++ b/service/models/operations/simulate.py
@@ -24,7 +24,7 @@ class Simulate(OperationRequest):
     pyciemss_lib_function: ClassVar[str] = "sample"
     model_config_id: str = Field(..., example="ba8da8d4-047d-11ee-be56")
     timespan: Timespan = Timespan(start=0, end=90)
-    policy_intervention_id: str = Field(..., example="ba8da8d4-047d-11ee-be56")
+    policy_intervention_id: str = Field(None, example="ba8da8d4-047d-11ee-be56")
     step_size: float = 1.0
     extra: SimulateExtra = Field(
         None,