Start with the oldest unreconciled period and work forward month by month. This matters because errors compound. A missing deposit in March throws off April, May, and every month after. If you start with December, you’ll chase discrepancies that originated months earlier and waste time adjusting entries that will change again once you fix the root cause.

Gather all bank statements for the periods you need to reconcile. Download them from your bank’s online portal or request copies if they’re beyond the typical online retention window. You’ll also need your accounting records for each period, specifically the general ledger detail for your bank account.

For each month, compare the ending balance on the bank statement to the ending balance in your books. The difference represents your total discrepancy. Then work through the components: deposits per the bank versus deposits per your books, withdrawals and checks per the bank versus what you recorded.

Common issues you’ll find include transactions recorded in your books but not on the statement, or vice versa. Some are timing differences that resolved themselves in subsequent months. Others are genuine errors like duplicate entries, transactions recorded to the wrong account, or expenses that were never recorded at all.

Make a list of every discrepancy before you start entering adjustments. You need to understand the full picture before changing anything. Some apparent errors offset each other. Others require research to determine whether the bank or your books were correct.

When you find transactions on the bank statement that aren’t in your books, add them with the original transaction date. When you find transactions in your books that don’t belong, void or delete them. When amounts differ, adjust to match the bank unless you have documentation showing the bank made an error.

After correcting a month, the reconciled balance should match the bank statement exactly. Then move to the next month. Each subsequent period should be easier because you’ve already corrected upstream errors.

If you’re years behind, consider whether full historical reconciliation is worth the effort. Sometimes drawing a line and starting fresh with a journal entry that forces the book balance to match the bank makes more practical sense. Premium business accounting in Boca Raton often involves making this judgment call based on materiality and how the records will be used going forward.

The harder question is what to do with discrepancies you can’t explain. If you’ve researched a $500 difference from 2021 and can’t determine the cause, you eventually need to write it off to an income or expense account and move on. Document what you know and what you tried.

This type of work falls under financial records cleanup and can be time-consuming depending on how many months need attention and how messy the records became. The goal is accurate, reconciled financials that you can trust going forward, even if the historical path to get there required some judgment calls.