If a payment fails

Nothing gets cut off the second a payment bounces, so don't panic if you see one fail.

1. I email you to let you know it didn't go through.
2. Your access stays on. The card gets retried automatically over about two weeks, so a lot of these sort themselves out without you doing a thing.
3. If it keeps failing, update your card on your account page and the next retry clears it. See Updating your card.

Only if it still won't go through after all the retries does the membership actually lapse. And even then, your journal is safe. Nothing you've saved gets deleted, so if you sort the payment or rejoin later, everything's still there. More on that in What happens to your journal if you leave.

If you'd rather stop than fix it, that's Cancelling, and it's a different button.