If your Balance Sheet is currently in balance with the personal bank account showing a balance in the account then when you remove the account balance you must also affect another account. For most setups using the prior fiscal year numbers the balancing account for removing the bank amount would be the retained earnings account. You can, however, use whichever account you wish but you must retain balance. As it is a personal account maybe the Shareholders Loan (or similar) account would be more appropriate. Once cleared, the bank account will still not be able to be deleted but you can mark it Inactive.