Most of what makes a tax return expensive is not the return. It is the reconstruction work that happens first. A clean set of books shortens preparation, reduces the number of questions you have to answer, and makes the result something you can actually rely on when planning.

Here is the order we generally work in, and the order you can follow yourself.

1. Reconcile bank and credit-card accounts

Start here, because nothing downstream is trustworthy until it is done. For every business bank account, credit card, and line of credit, confirm that the ending balance in your accounting file matches the year-end statement for every month.

Watch for the two classic problems: duplicate transactions from a bank feed that was reconnected mid-year, and old uncleared items sitting in the register from prior periods. Both quietly distort the numbers.

2. Separate personal transactions

Mixed personal and business spending is the most common cleanup issue we see. Go through the year and identify anything personal that ran through a business account, and anything business-related paid personally.

Personal spending from the business is generally recorded as an owner draw or distribution rather than an expense. Business costs paid personally may still be deductible by the business if properly recorded, depending on structure and how the reimbursement is handled. Either way, the goal is to stop guessing at year-end — a dedicated business account and card removes most of this work permanently.

3. Review uncategorized activity

Open the uncategorized or “ask my accountant” account and clear it. A large uncategorized balance almost always means real deductions are missing or income is misstated.

Work from the largest amounts down, and be specific: “office supplies” is not a home for a $9,000 equipment purchase. Where you genuinely do not remember, pull the receipt or the vendor statement rather than assigning a placeholder.

4. Verify income

Compare recorded revenue with independent sources: merchant processor deposits, invoicing system totals, and any information returns you expect to receive, such as Forms 1099-NEC or 1099-K.

Two frequent errors: recording the net deposit from a payment processor instead of gross revenue with a separate fee expense, and counting a customer deposit as revenue before it is earned. Both change the picture materially.

5. Review loans and lines of credit

Loan payments are not fully deductible expenses. Principal reduces the loan balance; only the interest portion is generally an expense. Pull the year-end amortization schedule or lender statement for each loan and confirm the split, then confirm the remaining balance matches the lender’s figure.

Do the same for any owner loans in either direction. Those are balance sheet items, and they matter for basis and distribution questions.

6. Review fixed assets

Identify purchases during the year that should be capitalized rather than expensed — equipment, vehicles, machinery, and significant improvements. Confirm that anything sold, traded, or scrapped has been removed from the asset list, since disposals affect the return.

Keep the invoice for each asset with the in-service date. Depreciation elections depend on it, and IRS Publication 946 is the primary reference for how property is depreciated.

7. Check payroll and sales-tax balances

If you run payroll, reconcile wages and withholdings in the books to your quarterly employment tax returns and year-end forms. Liability accounts should reflect only amounts actually still owed at year-end; stale balances usually mean a payment was recorded incorrectly.

Do the same for sales tax: the liability account should tie to filed returns and remaining obligations. Sales tax collected is not revenue, and treating it as revenue overstates income.

8. Gather year-end statements

Collect December statements for every bank account, credit card, loan, and merchant processor, along with any brokerage or investment statements held by the business. Independent third-party documents are what make the books verifiable rather than merely internally consistent.

9. Review accounts receivable and payable

Open the A/R aging and confirm every listed invoice is genuinely still owed. Long-outstanding invoices that were paid but never matched, or invoices duplicated by a system import, inflate income for accrual-basis taxpayers.

Review the A/P aging the same way. Bills already paid but never marked as such overstate liabilities and can distort expenses.

10. Document unusual transactions

Write a short note for anything out of the ordinary: an owner contribution, an insurance settlement, a grant, an equipment trade-in, a large refund, a related-party transaction. A sentence written now saves an hour of reconstruction later and gives your preparer the context needed to treat it correctly. General recordkeeping expectations are outlined in IRS Publication 583.

When professional cleanup is appropriate

Handle it yourself if the gaps are small and recent. Bring in help when:

  • accounts have never been reconciled, or have not been reconciled in months;
  • multiple years are behind;
  • the file was converted between software packages and balances shifted;
  • prior-year ending balances do not match the last filed return;
  • payroll or sales tax liabilities do not tie to filed returns;
  • personal and business activity are thoroughly mixed;
  • a lender, buyer, or agency needs reliable financials on a deadline.

Cleanup is quoted separately from ongoing monthly bookkeeping, because the cost depends on how many periods are behind and the condition of the file. That keeps your recurring fee tied to normal activity instead of the cost of fixing history. Ongoing service options are described on our bookkeeping page.

Talk it through with AEM

Every situation described here depends on facts that are specific to your business. AEM Accounting Solutions reviews your circumstances, explains the options in plain language, and quotes the work in writing before anything starts. You can request a personalized quote or see how engagements are priced on our pricing page.

This article provides general educational information and is not individualized tax, legal, or accounting advice. Tax treatment depends on the taxpayer’s specific circumstances and applicable federal and state law.