You are the best kind of patron, wanting to make sure that your favorite creators get paid.
If you go to update your card information and you receive a prompt for a phone number, or a code sent by phone, that is Stripe (who processes credit cards for us)- attempting to recall your information, and verify your identity. The problem is that Stripe can't actually update your info from Patreon, so if there is a new expiration date or a new number altogether, you would need to add the card as a whole new payment.
To add the card as a new payment method, instead of entering the code that gets sent, click the back arrow on the top left of the stripe popup to go back a page and enter new information. If you don't see that back arrow, you can also click the 'Log Out' option on the prompt to enter new card information.
Once you're done with that you can transfer your payments to the new card, or if you delete the old card you will be prompted to transfer the payments over.
If you are still having difficulty, send us a note HERE.