If you need to use an opening balance to setup new accounting for an existing business (like a credit card in use, but they only want transactions entered for the current year), do you have to create a journal entry later to clear out the "opening balance" category? I thought Opening balance should always be zero, but how do I get those amounts out of there?

So a credit card with transactions in December & January, statement date is Jan. 10; I need to reconcile it without bringing in all the transactions from December. So do I add those and create an "opening balance" with the sum? Then will it reconcile properly when I add all the January transactions?

Then, won't the balance sheet show that sum in the Opening Balance Equity account? How do I make a journal entry to remove that?

Let us assume, for sake of argument, that the transactions for the prior year have been recorded in the books, the opening balance should therefore exist as a creditor if not a specific bank account and when payment is made the transaction will reduce that balance to zero, you are then in the position of identifying the transactions in the new year. If the transactions were not recorded then your reconciliation will detail all outstanding transactions and an appropriate adjustment will need to be made in the balance date adjustmenst