app/refunds.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/app/refunds.py b/app/refunds.py
index b9e9744..1d3877e 100644
--- a/app/refunds.py
+++ b/app/refunds.py
@@ -2,7 +2,18 @@ from app.db import db
 from app.stripe import refund
 
 
+MAX_PER_HOUR = 3
+
+
+class RefundRejected(Exception):
+    pass
+
+
 def create_refund(order_id, amount, agent):
+    if db.refunds.count(order_id=order_id, amount=amount, since_seconds=60):
+        raise RefundRejected("duplicate refund within a minute")
+    if db.refunds.count(order_id=order_id, since_seconds=3600) >= MAX_PER_HOUR:
+        raise RefundRejected("refund limit reached for this order")
     order = db.orders.get(order_id)
     refund(order.payment_intent, amount)
     db.refunds.insert(order_id=order_id, amount=amount, agent=agent)