Most Ontario businesses close their books on December 31. The work you do in October and November decides how smooth, fast and affordable your year-end and tax filing will be. Leave it until March and you’re chasing missing receipts, untangling unreconciled accounts and paying for hours of clean-up.

Here’s the checklist we walk our own clients through each fall.

1. Reconcile every bank and credit card account

Match each transaction in your books to your statements, month by month, for every business bank account, credit card and line of credit. Unreconciled accounts are the single biggest cause of year-end delays. If you’re several months behind, start with the oldest month and work forward.

2. Review your accounts receivable

• Follow up on overdue invoices now, while there’s still time to collect before year-end.
• Identify invoices that realistically won’t be paid. Genuinely uncollectible amounts may qualify as bad debts, which your accountant can review.
• Check for duplicate or incorrect invoices that inflate your revenue.

3. Review your accounts payable

Confirm that every bill you owe is recorded, and that nothing already paid is still showing as outstanding. Missing bills understate your expenses; duplicate ones overstate them.

4. Gather and organize receipts

Every expense you deduct should be supported by a receipt or invoice. Scan or photograph paper receipts and store them with your records. It’s far easier to find a receipt from October in October than in April.

5. Separate personal and business transactions

If personal purchases went through the business account, or business expenses were paid personally, flag them now so they can be recorded correctly. For incorporated businesses, this can affect shareholder loan balances, which need careful treatment.

6. Check payroll records

• Confirm payroll remittances to the CRA are up to date.
• Make sure employee information is current ahead of T4 season.
• Remember that Ontario’s minimum wage rose to $17.95/hour on October 1, 2026. Confirm your pay rates were updated.

7. Reconcile your HST

Compare the HST you’ve collected and the input tax credits you’ve claimed against your filed returns. Quarterly filers have a return for July to September generally due October 31, so this is a natural time to check the year so far.

8. Take stock of inventory and fixed assets

If you carry inventory, plan a count close to year-end. List any equipment, vehicles or computers bought or sold during the year, since these are treated differently from day-to-day expenses.

9. Plan major purchases and decisions before December 31

Timing can matter for tax purposes, whether it’s buying equipment, paying bonuses or deciding how owners will be paid. Talk to your accountant before year-end rather than after, while decisions can still be made.

10. Decide who will handle it

If this list feels overwhelming, you’re not alone. Many business owners fall behind on bookkeeping simply because running the business comes first. Getting help now, rather than in tax season, costs less and reduces stress.

Get your books year-end ready

Our team handles monthly bookkeeping for small and medium businesses across Mississauga and the GTA, including catch-up and clean-up work. Monthly bookkeeping starts from $300. Learn more about our bookkeeping services in Mississauga, or call 905-279-6367 for a free consultation.

This article provides general information and isn’t tax advice. Every business is different; contact us to discuss your situation.