There are a few reasons why you might be in credit. If you’ve paid for something that you later return and is refunded, for example. Or perhaps your card provider issued a refund for a late payment fee on a previous balance.
You may have paid you last credit card bill twice by mistake or perhaps you paid more than the outstanding balance.
If you’d rather not have the extra credit on your card, you can ask your card provider to transfer the credit amount into your bank account.