Amazon takes it out of your available balance in your account if you’ve sold enough. Otherwise they hit your credit card. So if the card declines, your account is blocked until you supply a valid CREDIT card they can charge.

Best to downgrade to individual seller until you have sold enough to have a positive account balance.

But regardless of account type, you must have a valid card on file. If it declines, your account is locked and you don’t get paid. The credit card is Amazon’s insurance that they will get paid their fees and it helps slow down the scammers.

There are two selling plans available to Marketplace sellers: Individual, for smaller sellers with only a few items to offer; and Professional, for experienced and volume sellers. Sellers can switch their selling plan in the Settings area of their seller account.

Maybe a banned user/seller used the same street address, domain, or IP address. Try applying with a different email address, street address, IP address, etc.