How do I register for an HST number?

You register for HST through your CRA business number — online in about ten minutes. Registration becomes mandatory once you pass the small-supplier threshold.

An HST number is really an HST account attached to your CRA business number. If your corporation already has a business number (every incorporated business does), you are adding an RT program account to it.

When registration becomes mandatory

Once your taxable revenue passes $30,000 over four consecutive calendar quarters (or in a single quarter), you are no longer a small supplier and must register. Most incorporated businesses pass this quickly — and many register voluntarily from day one, because registration lets you claim back the HST you pay on business expenses as input tax credits.

How to actually do it

Three ways: online through CRA’s Business Registration Online (fastest), by phone with CRA’s business line, or by mail with form RC1. You will choose a filing frequency (annual, quarterly, or monthly — CRA assigns options based on revenue) and a fiscal year for the account.

What changes after you register

You charge HST on taxable sales, file returns on your schedule, and remit the difference between the HST you collected and the HST you paid. Registering late is the expensive version: CRA can require you to remit HST you should have collected but didn’t.

This is general information, not tax advice for your situation. Book a call and a Canadian accountant will give you the answer for your business.

Common questions

Should I register before I hit $30,000?

Often yes. Voluntary registration lets you claim input tax credits on your startup costs, and it avoids the awkward mid-year switch from not charging to charging. Your accountant can confirm the right timing for your situation.

I passed the threshold months ago and never registered. What now?

Register now, and talk to an accountant first. CRA generally expects HST from the date you crossed the threshold, so the sooner the account is set up and the exposure scoped, the smaller the problem.