diff --git a/golem_messages/constants.py b/golem_messages/constants.py
index 3378890..abfae9c 100644
--- a/golem_messages/constants.py
+++ b/golem_messages/constants.py
@@ -25,6 +25,9 @@
 # Force Acceptance Time
 FAT = 4 * CMT
 
+# Additional Verification Call Time
+AVCT = 3 * CMT + FAT
+
 # Payment Due Time
 PDT = datetime.timedelta(hours=12)