A contract is not required for monthly or annual subscriptions or at any membership level to ProxioPro. If you upgrade your ProxioPro account to any membership level, monthly or annual, you can cancel your membership at any time. Simply let us know via email (firstname.lastname@example.org). Please also see here for the FAQ on how to cancel your membership.
Memberships automatically renew from the date your sign up for both Monthly and Annual memberships: Standard Agent, Premium Agent and Global Agent.
i.e. if you sign up on 4/17/14 for a Standard Agent Monthly membership, your subscription will renew the next month on 5/17/14. If cancellation is needed, you can either call or send an email prior to the date of renewal.