diff --git a/src/fiber_package/events/activity.py b/src/fiber_package/events/activity.py
index bf63afa..0ee85dc 100644
--- a/src/fiber_package/events/activity.py
+++ b/src/fiber_package/events/activity.py
@@ -1,6 +1,8 @@
 from typing import Annotated, Self
 
 from .communication import CommunicationModel
+from .submodels import ActivityPaymentInfo
+
 
 class ActivityModel(CommunicationModel):
     category: Annotated[
@@ -11,12 +13,14 @@ class ActivityModel(CommunicationModel):
     start_time: datetime
     end_time: datetime
 
+    payment_info: ActivityPaymentInfo | None = None
+
 
     #signuplist: GroupRef | None = None
     # TODO: implement signup list (huge modular system)
 
     # TODO: see Felt 'activiteiten' DB schema. Things like:
-    # costs, payment method, email, target group, maximal attendees ....
+    # email, target group, maximal attendees ....
 
     @model_validator(mode='after')
     def check_end_after_start(self) -> Self:
diff --git a/src/fiber_package/events/submodels.py b/src/fiber_package/events/submodels.py
new file mode 100644
index 0000000..e933c02
--- /dev/null
+++ b/src/fiber_package/events/submodels.py
@@ -0,0 +1,10 @@
+from decimal import Decimal
+from typing import Annotated
+
+from pydantic import BaseModel, Field
+
+class ActivityPaymentInfo(BaseModel):
+    contribution: Annotated[Decimal, Field(decimal_places=2, ge=0)]
+    nnv_contribution: Annotated[Decimal | None, Field(None, decimal_places=2, ge=0)] = None
+
+