Does C3 have a minimum contract or lock in period after sign-up? No. Currently we don’t have a lock-in period for C3 subscription. By user|2020-06-18T19:21:31+00:00May 14th, 2020| Share This Story, Choose Your Platform! FacebookTwitterLinkedIn About the Author: user Leave A Comment Cancel replyComment Save my name, email, and website in this browser for the next time I comment.