How much does Flex cost me? November 21, 2019 18:21 Updated Our membership fees start at $14.99/month. This charge is taken on the same day as your final monthly payment. Related articles How does Flex work? What banks does Flex work with? When will my rent get paid? I finished signing up. Will my rent get paid? My property isn't listed. What should I do? Comments 0 comments Article is closed for comments.