u/hythloday1

Coupon code is SAVE27

It works on the next purchase of a year's worth of B1G+, so if you're a new subscriber it just knocks down the immediate purchase price. But if you're a current subscriber, the way it works is that you put in the code now (on the Purchases tab of your account page), and the discount applies to the scheduled renewal date then.

So the key thing is, the coupon code expires shortly, and the time to use it is right away ... even if you decide later not to renew, the coupon code doesn't obligate you for anything, you can just cancel the planned subscription renewal right up until the trigger date. (It might be a good idea to set a calendar reminder for a couple days before the renewal date to make a decision.)