The first thing to do is resist the urge to start deleting or changing transactions right away. Before you touch anything, document what you found. Write down which accounts are affected, what the error is, and which months it impacts. This gives you a clear picture of the scope before you start making corrections that could introduce new problems.

Next, figure out whether you’re dealing with a one-time mistake or a recurring pattern. A single miscategorized expense is easy to fix. But if you’ve been categorizing owner draws as an expense for six months, or if bank reconciliations haven’t been done and transactions are duplicated across several periods, the cleanup is more involved. Knowing the scope tells you whether this is a quick fix or something that needs a more careful approach.

When you’re ready to correct things in QuickBooks, use adjusting journal entries rather than deleting old transactions. Deleting removes the audit trail, and if those months were already reconciled or used for tax filings, you can undo work that was otherwise correct. An adjusting entry moves the amount to the right account while preserving the original record. For simple miscategorizations, you can usually just edit the category on the transaction itself without affecting the reconciliation.

Check whether the errors affect any tax filings you’ve already submitted. If you filed quarterly reports or an annual return based on incorrect numbers, you may need to discuss amended filings with your tax preparer. Small categorization errors between two expense accounts usually don’t change your total deductions, but errors that mix up personal and business spending, overstate revenue, or misclassify assets can have real tax consequences.

Once corrections are made, reconcile the affected months again to make sure everything balances. A corrected set of books should produce clean reconciliations with no unexplained differences. If the numbers still don’t tie out after your fixes, there may be additional errors you haven’t found yet.

Put a system in place to prevent the same errors from happening again. Most bookkeeping mistakes come from inconsistency. Transactions get categorized differently from month to month, reconciliations get skipped, or entries pile up and get rushed through all at once. Monthly reconciliation and consistent categorization rules catch errors when they’re small and recent, not months later when context is gone.

If the errors go back several months or you’re not confident making the corrections yourself, a bookkeeper in Long Beach can help you work through it systematically. Catch-up bookkeeping exists specifically for this situation, cleaning up past records so your books are accurate and ready for tax time without the risk of creating new problems while fixing old ones.