no, credit cards can't be directly used for repayment, so it's impossible to transfer money from other credit card accounts to credit cards for repayment. Now, the third-party online repayment platform usually only supports debit cards (savings cards) or third-party payment platform account balances to repay credit cards, but can't transfer them from credit card accounts.

the possible way to realize mutual repayment between credit cards is to use one credit card to withdraw cash and then repay another credit card, but this will generate corresponding interest and handling fee for withdrawing cash. If the operation is repeated repeatedly, it will only increase the interest and handling fee continuously, which is commonly called "keeping cards with cards". This method can be used for short-term working capital, but it is definitely not recommended for long-term use.