The extra money paid on the credit card will not be deducted by the bank, but will still be in your credit card account, which is equivalent to saving a sum of money in your credit card. It's just that the money won't generate any interest and will be offset when it is returned next month.

But the extra money on a credit card can't be withdrawn at will like a current deposit. If you want to take the extra money out of your credit card, you need to pay a certain handling fee. Equivalent to the credit card withdrawal fee.

Don't worry too much about returning the credit card. You can leave the money in your credit card and use it to deduct the next repayment. You only need to reduce the amount paid this time when you make the next repayment.

Extended data:

If you are worried about paying too many credit cards, you can choose to apply for a debit card from your peers at the same time and then bind two bank cards. As long as the balance in the debit card is sufficient, the bank will automatically deduct money from the debit card to pay back the credit card every month, and there will be no situation of paying back too many credit cards. There will be no overdue repayment.

The interest on the money in the debit card is calculated according to the current deposit. If you don't want to deposit with a debit card, you just need to deposit enough money to pay back your credit card two days before the monthly repayment date.

References:

Sogou encyclopedia-credit card repayment