The Bank Reconciliation Formula, Explained
There is no magic one-line formula. A reconciliation is two controlled adjustments that must reach the same answer.
The two sides of the formula
The bank and your books observe transactions at different times. Reconciliation does not force one raw balance to equal the other. It adjusts each side for items that belong to the period but are missing or wrong in that source.
For the bank side, begin with the ending balance printed on the statement. Add deposits recorded in your books but not yet posted by the bank. Subtract checks, payments, or withdrawals recorded in your books but not yet posted. Correct a bank error on the bank side until the institution resolves it.
For the book side, begin with the cash balance in your ledger. Add interest or receipts the bank recorded first. Subtract fees, returned deposits, automatic payments, and other bank debits not yet in your books. Correct recording mistakes in the ledger itself.
A worked example
Suppose the statement ends at $8,420. Your books show a $1,250 deposit that reached the bank the next day and a $670 check that has not cleared. The adjusted bank balance is $8,420 + $1,250 − $670 = $9,000.
Your ledger shows $9,035. The statement includes $15 of interest and a $50 service fee not yet recorded. The adjusted book balance is $9,035 + $15 − $50 = $9,000. The balances reconcile, and the interest and fee still need entries in the books.
What the formula cannot decide for you
The arithmetic cannot determine whether an unmatched item is a legitimate timing difference, a duplicate, an incorrect cutoff, or an unauthorized transaction. That classification requires source evidence. It also cannot justify plugging an unexplained amount into a suspense account merely to make the totals equal.
Automated extraction can accelerate the matching, but the same rule applies: preserve transaction identity, dates, and source references. A mathematically balanced file can still contain two offsetting errors, so spot checks and exception review remain important.
Frequently asked questions
Do outstanding checks change the book balance?+
Not during reconciliation if they were already recorded when issued. They reduce the adjusted bank balance because the bank has not posted them yet.
Where do bank fees go?+
A bank fee present on the statement but absent from the ledger reduces the adjusted book balance and normally requires an expense and cash entry.
Sources and further reading
We prioritize regulators, public agencies, and first-party product documentation. Sources support the general guidance above; StatementMint’s workflow recommendations are our own.
- Balance Your Checkbook: understand and reconcile your statementFederal Deposit Insurance Corporation
Educational information only—not financial, accounting, tax, or legal advice. Institution terms and your facts control.