Board Game Arena

I'm a premium subscriber, and my subscription is about to renew, but I need to change the credit card. I don't see a way to do that. Do I wait until close to the end of the subscription and then cancel my subscription and start a new one? Thanks in advance!

Short answer, you can't : /
You have to start a new one

I don't think you need to wait till close to the end. You can cancel it now and you keep your premium status until the end of paid period.