diff --git a/rero_ils/modules/patron_transaction_events/api.py b/rero_ils/modules/patron_transaction_events/api.py
index 8287537435..e7bb83faff 100644
--- a/rero_ils/modules/patron_transaction_events/api.py
+++ b/rero_ils/modules/patron_transaction_events/api.py
@@ -82,7 +82,9 @@ def create(cls, data, id_=None, delete_pid=False,
         """Create patron transaction event record."""
         if 'creation_date' not in data:
             data['creation_date'] = datetime.now(timezone.utc).isoformat()
-        data['amount'] = round(data['amount'], 2)  # ensure multiple of 0.01
+        if 'amount' in data:
+            # ensure multiple of 0.01
+            data['amount'] = round(data['amount'], 2)
         record = super().create(
             data, id_, delete_pid, dbcommit, reindex, **kwargs)
         if update_parent: