Monthly Bookkeeping Checklist: How to Close Your Books Each Month

A monthly bookkeeping checklist is a fixed set of steps you run after each month ends so your numbers are complete, reconciled, and locked. Done consistently, it turns your books from a pile of transactions into reports you can actually make decisions with.

Most small businesses need that clarity. In the Federal Reserve's Small Business Credit Survey, 94% of small employer firms reported facing a financial challenge in 2024. Closer to home, the Philadelphia Fed found that 67% of New Jersey small businesses described their financial condition as fair or poor in 2025 (457 firms surveyed).

This guide walks through a 10-step month-end close for small business, a New Jersey compliance calendar, and the mistakes that cause trouble at tax time. Use it to run the close yourself, or as a yardstick if you're weighing outsourced monthly bookkeeping services.

Key Takeaways

• Close your books every month: record transactions, reconcile every bank and card account, review receivables and payables, post adjustments, then review and lock the period.
• Reconciliation is the step you can't skip. If your books don't match your bank statements, every report built on them is off.
• Federal payroll tax deposits for monthly depositors are due by the 15th of the following month (IRS Topic 757).
• New Jersey sellers file Form ST-50 quarterly, and larger sellers also make monthly payments by the 20th (NJ Division of Taxation).
• Locking a closed month in QuickBooks or Xero protects your reconciled numbers from accidental edits.

What is a month-end close?

A month-end close is the process of finalizing your accounting records for a month so the balances are accurate and stop changing. After the close, your profit and loss statement, balance sheet, and cash flow report for that month should be reliable enough to share with a lender, a tax preparer, or a business partner.

The work you do depends partly on your accounting method. Under the cash method, you record income when you receive it and expenses when you pay them. Under the accrual method, you record income when you earn it and expenses when you incur them, regardless of when cash moves. IRS Publication 538 explains both methods and who can use each. If you're on the cash method, some steps below (like accruals) will be lighter.

What you need before you start

Gather everything in one place before you open your accounting software. Hunting for a missing receipt halfway through is how a two-hour job becomes a two-day job.

• Bank and credit card statements for every business account, including any you rarely use
• Receipts and bills for the month, paper or digital
• Sales records from your invoicing system, POS, or e-commerce platform
• Payroll reports from your payroll provider
• Loan statements showing the principal and interest split
• Last month's closed reports so you can compare
• Access to your accounting software with permission to close periods

The 10-step monthly bookkeeping checklist

These steps follow the standard month-end sequence laid out in Xero's month-end close guide. Work through them in order, because later steps depend on earlier ones being right.

Step 1: Record and categorize every transaction

Start by making sure every sale, expense, and transfer for the month is in your books. Pull in bank feeds, enter cash transactions, and attach receipts.

Then check categories. A software subscription coded to "Office Supplies" won't break anything this month, but it will distort your expense trends and can complicate your tax return. Clear out any "uncategorized" or "ask my accountant" items before moving on.

Step 2: Reconcile bank and credit card accounts

Reconciliation means matching your book balance to your statement balance, line by line, for every bank account and credit card. This is the single most important step in the close.

1. Open the reconciliation tool in your software and enter the statement's ending balance and date.
2. Tick off each transaction that appears on both the statement and your books.
3. Investigate anything left over: missing entries, duplicates, or amounts typed wrong.
4. Finish only when the difference is zero.

You'll know it worked when the reconciled balance matches the statement exactly. Don't force a reconciliation with an adjustment you can't explain.

Step 3: Review accounts receivable

Your accounts receivable aging report shows who owes you money and for how long. Run it, compare the total to your balance sheet, and follow up on overdue invoices.

Late payments are common. In the QuickBooks 2025 Small Business Late Payments Report, 56% of small businesses said they were owed money from unpaid invoices, averaging $17,500. Xero's U.S. small business data for the June 2026 quarter showed businesses waited 29.3 days on average to get paid, with invoices paid 8.5 days late. A monthly review keeps those old invoices from quietly turning into bad debt.

Step 4: Review accounts payable

Run your accounts payable aging report to see what you owe and when it's due. Make sure every bill you received this month is entered, and that bills you've already paid are marked paid.

This is also a good moment to plan next month's cash. Knowing which large bills land in the first two weeks helps you avoid a cash crunch.

Step 5: Tie out inventory

If you carry inventory, compare the inventory value in your books to a physical count or your inventory system. Differences usually come from shrinkage, damaged goods, or receiving errors.

Record an adjustment for the difference so your cost of goods sold and gross margin are accurate. Service businesses without inventory can skip this step.

Step 6: Record accruals and prepaid expenses

Accruals put income and expenses in the month they belong to, even if cash moves later. For example, if you received a contractor's work in September but the invoice arrives in October, an accrual records that expense in September.

Prepaid expenses work the other way. If you pay a 12-month insurance policy upfront, you spread that cost across the 12 months it covers instead of booking it all at once. Businesses on the cash method will have fewer of these entries.

Step 7: Post depreciation

Record depreciation on equipment, vehicles, and other fixed assets each month. Many accounting tools let you set up a recurring journal entry so this happens automatically.

Monthly depreciation keeps your profit figures realistic. Without it, the month you buy equipment looks terrible and every month after looks better than it really is. Your tax depreciation may follow different rules, so confirm the method with whoever prepares your return.

Step 8: Record payroll entries and check tax deposits

Make sure gross wages, employer taxes, and withholdings from your payroll reports match what's in your books. Payroll providers often post only the net pay, which leaves taxes and benefits missing.

Then confirm your federal deposits are on schedule. Under IRS Topic 757, you're a monthly depositor if you reported $50,000 or less in employment taxes during the lookback period, and each month's deposit is due by the 15th of the following month. Larger employers deposit on a semiweekly schedule. If you accumulate $100,000 or more in tax liability on any day, it's due the next business day.

Step 9: Run and compare your financial statements

Run your profit and loss statement, balance sheet, and cash flow statement. Compare each one to the prior month and to your budget, if you have one.

Look for anything that doesn't make sense: a utility bill that doubled, a negative bank balance, or revenue that jumped without a reason. Then check a few key ratios. QuickBooks suggests tracking gross margin, net margin, accounts receivable turnover, the current and quick ratios, and the cash conversion cycle. If you want these packaged into a monthly report with commentary, that's what management reporting is for.

Step 10: Review and lock the period

Once everything checks out, lock the month so nobody can change it by accident. Xero's guide treats review and lock as the final step of the close.

In QuickBooks Online, go to Settings > Account and settings > Advanced > Accounting and turn on Close the books. You can add a password so changes to closed periods require approval, according to QuickBooks' help article. If someone does edit a closed period, the exceptions to closing date report shows what changed.

Monthly compliance calendar for New Jersey businesses

Your close should line up with your tax deadlines. The table below covers the recurring federal and New Jersey dates most small businesses face. Exact obligations depend on your size and registrations, so confirm yours with the source. For annual filing dates by entity type, see our 2027 small business tax deadline calendar.

A clean close makes each of these easier. Your sales tax payable account should match what you file, and your payroll liability accounts should drop to zero after each deposit. If you'd rather have someone track filings for you, see our tax compliance support.

Common month-end close mistakes

Most month-end problems come from skipping steps rather than doing them wrong. Watch for these:

• Closing without reconciling. It's tempting to run reports once the transactions are in. But unreconciled books can hide duplicates and missing entries, so your reports look right while being wrong.
• Mixing personal and business spending. Personal charges on a business card make categorizing harder and muddy your deductions. Use separate accounts and record any personal use as an owner draw.
• Letting "uncategorized" pile up. A few unclear items each month become hundreds by year-end. Resolve them during the close while you still remember what they were.
• Ignoring the balance sheet. Owners often look only at profit. A balance sheet with old receivables, negative balances, or unexplained loan amounts usually points to a deeper error.
• Editing closed months. Changing a period you've already reported throws off filed returns and past reports. Lock periods and use a password.

Should you close your books yourself or outsource?

You can run this checklist yourself if your business is simple: a few accounts, modest transaction volume, and no inventory. The real question is whether you'll do it every month, on time, without it slipping behind your actual work.

Outsourcing tends to make sense when the close keeps getting pushed back, when you have payroll and sales tax to manage, or when you need reports a lender or investor will trust. If you're comparing options, our guide to how much bookkeeping costs breaks down typical pricing models. And if you're already several months behind, a bookkeeping cleanup and catch-up gets you to a clean starting point before monthly work begins.

At Asquaire Financials, monthly bookkeeping starts at $249/month and management reporting at $299/month. Asquaire was founded by ACCA-qualified accountants with Big Four experience, is based in North Brunswick, NJ, and can run this checklist for you every month. Asquaire is not a CPA firm.

Frequently asked questions

How long does a month-end close take?

It depends on your transaction volume, the number of accounts, and how current your records are. A business that categorizes transactions weekly will close much faster than one that saves everything for month-end. Your first close after a cleanup usually takes the longest, and the process gets quicker once it becomes routine.

When should I close my books each month?

Start as soon as your bank and credit card statements for the month are available, usually in the first week or two of the next month. Aim to finish before the 15th so you can confirm payroll deposits, and before the 20th if you make New Jersey sales tax payments.

Do I need to use accrual accounting to close my books?

No. Cash-method businesses still need to record transactions, reconcile accounts, and review reports every month. You'll just have fewer adjusting entries. IRS Publication 538 explains which businesses can use the cash method.

What if I'm several months behind on my books?

Don't try to close the current month first. Work forward from the last month you know is accurate, reconciling each month in order. Our step-by-step guide on how to catch up on bookkeeping covers the process in detail.

Can I change a month after I've closed it?

Yes, but it should be rare and deliberate. In QuickBooks Online, a closed period can be edited if you have the password, and the exceptions to closing date report records each change. If a correction affects a tax return you've already filed, talk to your tax preparer before you change anything.

Close every month, not just at year-end

A monthly close takes your books from "mostly right" to reliable. Record and categorize, reconcile every account, review what you're owed and what you owe, post adjustments, check your reports, and lock the period. Do it every month, and tax season becomes a review instead of a rescue.

If you'd like a team to handle the close and send you clear reports each month, get in touch with us.

This article is general information, not tax or legal advice.