How to Reconcile a Checkbook Register. Many people attempt to keep track of their checking account balance by checking the ATM or logging into their personal accounts on their banking institution's website. These methods, however, are unreliable if you have forgotten about a check that you have written or a bank fee associated with a foreign ATM. The most reliable way to keep track of your bank account balance is by using your checkbook register and reconciling it at least once per month. To do this, you must keep track of all receipts for purchases and ATM withdrawals, all deposits that you have made and all checks that you have written.