HST for Ontario contractors, without the mystery

You must register for HST once your revenue passes $30,000 over four consecutive calendar quarters — or in any single calendar quarter, which happens faster than most expect. It's rolling, not per tax year. Most trades blow through that in their first busy season, often without noticing until a customer or a bookkeeper asks for their HST number.

Crossing the line without registering doesn't make the tax go away. The CRA treats your sales after the threshold as if they already included HST — so the tax (about 11.5% of what you charged) comes out of your pocket instead of being added on top of your invoices. Registering a little early is almost always cheaper than registering late.

In Ontario you charge 13% HST on top of your labour and materials for taxable work — which covers almost everything contractors do: renovations, repairs, installs, service calls, new builds for commercial customers.

Put the HST on its own line on every invoice, with your registration number. Customers expect it, the CRA requires it, and it makes your bookkeeping cleanly separable: that line was never your money.

Every dollar of HST you pay on business purchases — materials, fuel, tools, the accountant's bill — comes back to you as an input tax credit (ITC). Your remittance is the difference: HST you collected minus HST you paid.

ITCs are why receipts matter. No receipt, no credit, and on a materials-heavy job the credits are real money. A $40,000 materials year carries about $5,200 of HST you can only claim with the paper to prove it.

The HST you collect is the CRA's money sitting in your account, and it feels exactly like cash flow until the filing lands. The fix is mechanical, not motivational: every time a customer pays, move the HST line to a separate account the same day.

If your books are current, you always know your real position — collected minus credits — so the filing is a transfer, not a scramble. That number is on your monthly statement when we keep your books.

Most registrants start annual and can elect monthly or quarterly. Monthly and quarterly filers owe the return and the payment one month after the period ends. Annual corporate filers get three months after fiscal year-end.

Quarterly is the sweet spot for most trades: the amounts stay manageable, and you never sit on a year's worth of the CRA's money. Use our deadline tool to see your actual dates for the next twelve months.