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Hire an accountant when your taxable sales get close to $30,000 in a year, when you take on your first employee, or when you form a corporation. Each of those brings new filings with fixed deadlines, and a mistake costs real money.
When is it time to hire an accountant?
A sole proprietor with a few clients and simple costs can often file alone. Things change when the rules start to multiply. Taxable sales near $30,000 raise the question of GST/HST registration. Paying staff means holding back tax, CPP and EI. Moving from a sole proprietorship to a corporation is a third trigger, and so is buying a vehicle, equipment or property for the business.
Selling to customers in several provinces counts too, and so do books that have slipped more than a quarter behind, since a backlog that size rarely clears itself.
Getting help early is cheaper than fixing a bad year later. One hour with someone before you incorporate can keep you out of a structure that doesn’t fit your plans.
How close to the $30,000 line is too close?
Closer than most people think, because the test runs over four consecutive calendar quarters, not a calendar year. Say Priya, a web designer in Winnipeg, bills $6,000, $7,500, $8,000 and $9,500 in four quarters in a row. That adds up to $31,000, so she’s over the limit even though no single quarter looked big. In a case like that, the CRA’s page on who needs to register for GST/HST says you stop being a small supplier at the end of the month following the quarter in which you exceed it. Blow past $30,000 in one quarter alone, though, and you have to charge tax on the sale that took you over.
That’s a good moment for a short chat with an accountant. Not a year later, when you’ve been keeping tax you should have charged.
Which deadlines will an accountant help you meet?
| Filing | Deadline for the 2025 tax year (filed in 2026) |
|---|---|
| Self-employed tax return | June 15, 2026 |
| Tax owing for self-employed people | April 30, 2026 |
| Quarterly instalments | March 15, June 15, September 15, December 15 |
| T4 slips for staff | Last day of February |
| Corporation return (T2) | Six months after year end |
| Corporation tax balance | Two months after year end, or three for many small Canadian-controlled private corporations |
| GST/HST small supplier limit | $30,000 in a quarter or over four quarters |
The CRA’s due dates page for personal income tax lists the June 15 and April 30 dates. For T4s, the CRA’s page on when to file information returns says a due date that falls on a weekend or CRA-recognized holiday moves to the next business day. Late filing brings penalties and interest, and it’s the most common reason people phone a professional.
Two points trip people up. The June 15 date is only for filing, since the balance is still due April 30. And the three-month corporate balance date has conditions, such as claiming the small business deduction, per the CRA’s corporate payment due dates page.
What does the tax bill look like?
Start with a sole proprietor in Ontario who nets $60,000. Income tax comes to $7,879.42 and CPP to $6,723.50, since a self-employed person pays both halves. That’s $14,602.92, or 24.3% of income. The self-employed tax calculator will run your own figures.
Now a corporation in Ontario earning $300,000 of active business income. The corporate tax calculator shows $35,088 of tax, an average of 11.7%. At $600,000 the tax is $84,980, or 14.2%, because income above the small business limit is taxed at a higher combined rate of 26.5%. The gap between those two structures is where advice on salary versus dividends pays for itself.
Once your tax owing is large, instalments may apply, so check the tax instalments calculator before the first payment falls due.
What should you bring, and what should you ask?
Bring bank statements, sales invoices, receipts and any prior returns. Then ask what the fee covers, who files the GST/HST return and how they handle payroll. How fast do they answer questions between filings? Have they worked with businesses like yours? Fees vary a lot from one firm to the next, so get two or three written quotes and compare what each one covers as well as what it costs.
A bookkeeper records transactions. An accountant reviews them, files returns and advises on structure. Plenty of small firms use both, with the bookkeeper doing the monthly work and the accountant stepping in at year end.
What mistakes do business owners make?
- Waiting until the return is due. Records are easier to fix in the same year.
- Mixing personal and business spending in one account.
- Ignoring the small supplier limit and collecting tax late. A GST/HST calculator result only helps once you’re registered.
- Paying staff without a payroll account. The payroll remittance calculator shows what an employer must send in each pay period.
- Throwing out records early. Keep them six years from the end of the last tax year they relate to.
The calculators give estimates for a standard case. They don’t model associated companies, passive income rules or special credits, so have a professional look at anything unusual. Get that done before tax time, not in the last week of April.
Where the figures come from
Deadlines, the small supplier limit and the record keeping period come from Canada Revenue Agency pages for 2026. Tax figures in the examples come from the calculators on this site, which use published 2026 federal and provincial data. This is an independent guide, separate from any government body, and it doesn’t offer accounting services.
Frequently asked questions
When should a new business hire an accountant?
Before you incorporate, hire staff or reach $30,000 in taxable sales. Those steps add filings with fixed deadlines.
Do I need an accountant if I'm a sole proprietor?
Not always. With simple income and costs you can file alone, but a professional helps once GST/HST or payroll begins.
What's the difference between a bookkeeper and an accountant?
A bookkeeper records transactions. An accountant reviews the books, files returns and advises on structure and tax.
What records should I bring to the first meeting?
Bank statements, invoices, receipts, past returns and any GST/HST or payroll account numbers.
How long must I keep business records?
Six years from the end of the last tax year they relate to, unless the CRA allows earlier destruction.
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