The first thing to know is that you’re not the only one who’s let bookkeeping slide. Tax deadlines pass, work gets busy, and suddenly you’re staring at six or eight months of untouched transactions. It feels overwhelming, but it’s fixable.

Start by gathering everything. Bank statements for all business accounts, credit card statements, invoices you’ve sent to customers, receipts you’ve saved, payroll records if applicable. You can’t reconcile what you can’t see. Most banks let you download statements going back at least a year or two online. Pull those first.

Bank reconciliation is your foundation. Whatever else is messy, your bank statements are the truth. Every dollar that came in and went out is recorded there. Import your bank transactions into QuickBooks or whatever accounting software you use, then work month by month starting with the oldest incomplete period.

Work chronologically. Don’t jump around trying to fix recent months first. Your opening balance for each month depends on the prior month being correct. Start where your books stopped being reliable and move forward from there.

Use your bank statements as the backbone of the process. For each transaction, figure out what it was for and categorize it. Payments from customers are revenue. Payments to vendors are expenses or cost of goods sold. Transfers between your own accounts are just transfers. Checks you wrote need to be matched to what they paid for.

Keep a list of transactions you can’t identify. You’ll have some. A charge from three months ago at a merchant name you don’t recognize. A deposit you can’t tie to an invoice. Flag these and keep moving. You can research them later without getting stuck.

Reconcile each month before moving to the next. The bank balance in your books should match the actual bank balance at month end. If it doesn’t, something is off. Find the discrepancy before moving on, or it will compound as you work forward.

Tackle credit cards separately after bank accounts. Same process: import transactions, categorize each one, reconcile to your statement balance. If you’ve been using personal cards for business expenses, pull those business transactions into your books using an equity account.

Be realistic about your time. If you’re three months behind and have relatively simple books with one bank account and one credit card, you might knock it out in a weekend. If you’re eight months behind with multiple accounts, inventory, and payroll, you’re looking at potentially weeks of work doing it yourself. Our Andover, MA advisory services team sees this regularly and can often work through a year of transactions in a fraction of the time it would take someone unfamiliar with the process.

The goal isn’t perfection initially. It’s getting your books to a point where they’re reconciled and reasonably accurate. You can always refine categories later. What matters is that your accounts balance and your records reflect what actually happened.

If you’re significantly behind or the complexity feels impossible, professional catch-up bookkeeping help makes sense. Someone who does this regularly knows what to look for: duplicate entries, transactions coded to wrong accounts, reconciliation issues that need investigation. They also won’t get distracted by running the business while trying to fix the books.

Once you’re caught up, put a system in place so it doesn’t happen again. Weekly transaction categorization takes fifteen minutes. Monthly reconciliation takes an hour or two. That’s a lot easier than the marathon cleanup you’re facing now.