When should you register for GST/HST?

Almost every growing business hits this question in the same way. Revenue climbs quietly for a year, somebody asks whether HST should have been on those invoices, and the answer turns out to depend on a threshold that was crossed several months earlier. Here is how the rule actually works, and why waiting for it to force your hand is usually the wrong move.

The $30,000 small supplier threshold

You are a small supplier, and therefore not required to register, while your worldwide taxable revenue stays at or below $30,000 over four consecutive calendar quarters. The measure is your gross taxable supplies, before expenses, and it includes zero-rated sales. It is not tied to your fiscal year end. It rolls, quarter by quarter, on the calendar.

There are two different ways to lose small supplier status, and they carry different dates.

You go over inside a single calendar quarter. You stop being a small supplier immediately. The sale that took you past $30,000 is itself taxable, your effective date of registration is the day of that sale, and you have 29 days from that day to register.

You go over across four consecutive quarters, without any single quarter exceeding $30,000. You stay a small supplier for one further month after the end of the quarter in which you crossed the line. Your effective date of registration is the day of your first taxable sale after that month ends, and again you have 29 days from that day to register.

Take a business with quarters of $6,000, $8,000, $9,000 and $8,000. The total is $31,000, so the threshold was crossed in the fourth quarter, but no single quarter went over on its own. That business stays a small supplier through the following month, then registers and starts charging from its next sale.

A separate rule catches taxi and ride-share drivers, who must register regardless of revenue.

What you charge once you are registered

In Ontario, the rate is 13% HST. Ontario businesses file a single HST return covering the federal and provincial portions together, so there is no separate provincial sales tax filing to worry about.

Not everything you sell is necessarily taxable at 13%. Some supplies are zero-rated, which means you charge 0% and still claim input tax credits on your costs. Others are exempt, which means you charge nothing and cannot claim credits on the related expenses. Many health and wellness services fall into that second category, and the distinction changes the whole economics of registering. Our HST exempt or taxable lookup is a starting point for where a given service sits.

Why registering early is often worth it

The obligation is one thing. The arithmetic is another, and the arithmetic often favours registering before you are required to.

Input tax credits on start-up costs. A registrant recovers the HST paid on business purchases. A small supplier who has not registered recovers nothing. For a business in its first year, the HST buried in equipment, tools, software, professional fees, leasehold improvements and marketing spend can be a serious number, and once those costs are consumed the credits are gone for good. There is limited relief for property still on hand when you register, but it does not extend to services and expenses you have already used up. Every month you delay registration is a month of credits written off.

Your customer base decides whether it costs you anything. If you sell to other registered businesses, they claim back the HST you charge them, so registering has no real effect on your price. If you sell to consumers, adding 13% is a genuine price increase you either absorb or pass on. That single question, business customers or retail customers, usually settles whether early registration is a clear win or a trade-off.

Credibility and clean books. A supplier without a GST/HST number reads as very small to a corporate buyer. Registering also forces the reporting discipline you will need anyway.

The cost of registering late

The CRA's position is that you were required to collect from your effective date, whether or not you did. That means the tax comes out of revenue you already banked, plus interest, plus penalties on late returns. Going back to customers a year later to ask for 13% they were never invoiced is a conversation almost nobody wins.

After you register

Your filing frequency is assigned based on annual taxable supplies, with smaller registrants filing annually and larger ones quarterly or monthly. You can elect to file more often than required, which many new registrants do, because a year's worth of unfiled HST is much harder to reconstruct than a quarter's. Getting the registration, the filing calendar and the bookkeeping set up at the same time avoids doing the same work three times.

Two things are worth setting up on day one. Charge and show HST correctly on every invoice, including your registration number, which customers need in order to claim their own credits. And keep the HST you collect out of the operating account, because it was never your money in the first place.

One more question to raise before your first filing: whether the Quick Method suits you. It lets eligible smaller registrants remit a flat percentage of sales rather than tracking every input tax credit, and for a service business with low input costs it can leave you remitting less than you collected. It works badly for a business with heavy purchases, so it is a calculation rather than a default.

All of our bookkeeping, hst and payroll work

General information only, current at August 2026. Tax rules change and GST/HST status is fact-specific. Confirm your own position before relying on anything here.