Monthly bookkeeping cleanup checklist for startups

The monthly close is the difference between books you can run a business with and books that are ornaments. Our bookkeeping team runs this exact 12-point checklist every month, on every client. Steal it.

Why monthly close matters

A clean monthly close gives you three things: financials you can actually use, a paper trail that holds up at tax time, and an early-warning system when something's drifting. Without it, you're driving by feel and finding out three months later that your gross margin compressed in March.

The 12-step checklist

1. Reconcile bank accounts

Match every line on the bank statement to a line in the books. Outstanding deposits, outstanding checks, and any cleared item missing from the books - fix all three. If the books don't tie to the statement to the penny, nothing else in the close matters.

2. Reconcile credit cards

Same drill. Pay extra attention to pending charges that posted after the cutoff - these belong to next month, not this one.

3. Reconcile loans and lines of credit

Match the principal balance per the lender's statement to your books. Split interest from principal on every payment - interest is an expense; principal is a balance-sheet reduction.

4. Review uncategorized transactions

Anything sitting in "Ask My Accountant" or "Uncategorized Expense" - clear it now. Ask the founder if you're not sure; never guess.

5. Review accounts receivable

Pull the AR aging. Flag anything over 30 days. Send reminders on 30+, get a phone call going on 60+, escalate or write off at 90+. Old uncollected AR rotting on the balance sheet inflates revenue artificially.

6. Review accounts payable

Pull the AP aging. Confirm everything in there is legitimate and current. Pay or schedule anything due in the next 15 days. Reverse anything that turned out to be a duplicate or got paid outside the AP module.

7. Reconcile payroll

Compare your payroll provider's reports (Gusto, Rippling, EazePayroll) to what hit the bank and what's in the books. Confirm employer taxes posted, contractor 1099s are categorized correctly, and any benefits/reimbursements landed in the right account.

8. Review fixed assets + depreciation

Any new equipment, software, or capital purchases over your capitalization threshold (usually $1k–$2.5k) should be on the balance sheet, not expensed. Run monthly depreciation on the schedule. Most cloud accounting tools do this automatically if set up correctly.

9. Review accruals and prepaids

Did you collect cash for work not yet delivered? That's deferred revenue. Did you pay for a year of insurance up front? That's a prepaid. Adjust accruals so the P&L reflects what actually happened in the month, not when cash moved.

10. Collect missing documents

Any expense without a receipt? Ask for it now. The further you get from a transaction, the harder it is to find the supporting doc. Build a culture of "receipt within 7 days."

11. Run the financials

Run a P&L, a balance sheet, and a cash flow statement for the month and YTD. Skim for anomalies - any account that moved more than expected gets a one-line explanation.

12. Sign off and lock the period

If you're using QuickBooks/Xero, set a close date so nothing can be edited retroactively without a password. Email the founder a one-paragraph close summary with the three numbers they care about most.

Common close mistakes

1. 1Leaving uncategorized transactions for "later." Later never arrives.
2. 2Closing without reconciling. The books look fine; they don't tie to reality.
3. 3Treating payroll as a single line. Burying employer taxes, benefits, and contractor pay together makes them invisible at tax time.
4. 4Not collecting receipts in real time. Tax season turns into archaeology.
5. 5Skipping months when business is slow. The compounding mess is brutal.

What to do next

Pick the 5th business day of every month as your close day. Block 2–3 hours, run this checklist, and email yourself the summary. Repeat for three months and the close goes from a chore to a 45-minute habit. Or hand it to a bookkeeper and stop thinking about it - that's literally what we do here.