All plans will auto-renew for the same term after your initial subscription term has been completed. This means that after a year, the yearly plan will auto-renew for another year and the quarterly plan will auto-renew for another quarter.
If you have signed up for the trial program, after the 3 months free, you will be billed for the annual plan on the 91st day. Your plan with auto-renew a year after the 91st day, not on the day you started your free 3 months.
If you would like to not auto-renew your subscription, please contact a member of Customer Support HERE.