It might be an understatement to say that MoviePass isn't doing too well these days. Many of the service's subscribers (including myself) have stuck aboard the sinking ship anyway to save a bit of cash. But now that the company is imposing new restrictions on use—as well as a 50% price increase to $15 a month—it might be time to head to those lifeboats. Since you can't cancel the service easily via the company's site and there are restrictions on app access/authorization, here's a complete and detailed walkthrough on how to cancel your MoviePass subscription.
It's unfortunate you can't just cancel online, especially considering California now requires that subscriptions which are created online must be capable of being canceled online, and MoviePass is more than happy to let you sign up via its website.
All this means that you'll need to be signed in on the app to cancel service. Unfortunately, MoviePass not only limits device authorization to one phone at a time, but it also prevents you from switching phones more than once every 30 days.
The warning toast notification you'll receive trying to sign in on more than one device per month.
So if you freshly authorize a device and it gets lost or stolen, you'll need to contact support or sit around until that month runs out. It's a pretty stupid restriction, but sort of par for the MoviePass mismanagement course.
Although there are exceptions, you should keep in mind that canceling service will render you ineligible for renewal or a new subscription for nine months. Make sure you are OK with not using MoviePass for a minimum of nine months before proceeding.
As described above, you should either already have the app installed on a device you can access or be able to install it and sign in without the 30-day multi-device restriction in place in order to cancel service.
Once the app is installed and you are signed in, head to the "Account" tab at the bottom right. From there, open "Account Details." You should see the screen below.
There are technically two fields here that say "Cancel," but the one at the top of the screen is meant to cancel changes made on this page, not your account. You'll want to tap the red cancel text on the "Plan" line.
MoviePass actually requires for you to provide a reason for your cancellation from the drop-down menu at the top. In my opinion, any company that forces you to give an explanation as part of the membership cancellation process really deserves what they're asking for, so go ahead and give them your most brutally honest take. Odds are that MoviePass is well aware of your motivations for canceling already—or they really haven't been paying attention to the news—but feel free to lay bare your soul.
Again, note that if you cancel your membership, you can't come back to the service for nine months.
Once you've provided your motivation, tap the big "Cancel Subscription" button, and then select "CANCEL MEMBERSHIP" on the dialog that appears.
You should see the floating confirmation dialog above, with the date your subscription remains good until below. At this point, you're good to go. You can continue to use your account for the remainder of your billing period and rest easy knowing you won't keep paying for the service after that.
Whatever your motivation for leaving may be, you're now free.