Some codes have an expiration date, so make sure the one you are trying to use is valid.  Once applied to your paid subscription, your card will be charged once for the year at that discounted price and you won’t be charged again until the next year if you choose to continue with PRO. Any purchase made with a coupon is a straight purchase with no trial - it's a great price for a year long membership! It is charged all at once.

The coupon, however, only extends to a single year of the membership, unless otherwise noted.