The $30K Small Supplier Threshold — When to Register for GST/HST

Every Canadian business owner hears about the "$30K threshold" but the details are often misunderstood. Here's exactly how it works.

The Rule

You're a small supplier if your total taxable revenue (before expenses) is $30,000 or less over four consecutive calendar quarters and no single quarter exceeds $30,000. As a small supplier, GST/HST registration is optional.

Once you exceed $30,000 by either measure, you must register — and you must start charging tax on the supply that pushed you over the threshold. You have 29 days from the end of the month in which you exceeded the threshold to register.

How the Rolling Window Works

CRA looks at two things:

1. Your total revenue over any four consecutive calendar quarters
2. Your revenue in any single calendar quarter

If either exceeds $30,000, you must register.

Example — cumulative trigger: You earn $8,000 per quarter. After Q1-Q4, your rolling total is $32,000. You've crossed the threshold and must register.

Example — single quarter trigger: You land a big project and earn $35,000 in Q1, then $2,000 in each of Q2-Q4. You must register immediately after Q1 — you don't get to wait and see if the four-quarter total stays under.

Example — still under: You earned $15,000 in Q1, $5,000 in Q2, $5,000 in Q3, and $4,000 in Q4. No single quarter exceeds $30K, and the total is $29,000 — you're still a small supplier.

What Happens When You Cross It

1. You must register for a GST/HST account with CRA
2. You start charging tax on the transaction that put you over $30,000
3. You begin filing GST/HST returns (annually, quarterly, or monthly)
4. You can now claim Input Tax Credits (ITCs) on your business expenses

Should You Register Early?

Even if you're under $30K, voluntary registration lets you:

• Claim ITCs on business purchases (get the tax back)
• Look more professional to clients who expect to see a GST/HST number
• Avoid the scramble of retroactively charging tax mid-invoice

The downside: you must charge tax on all sales and file returns regularly.

For most businesses spending significantly on taxable inputs (equipment, software, supplies), early registration saves money through ITCs.

The Quebec Wrinkle

Quebec has its own $30K threshold for QST registration, calculated separately. If you sell to Quebec clients from outside the province, you must register for QST once your Quebec-specific sales exceed $30K.

Track It Automatically

Facturo monitors your rolling revenue and alerts you before you hit the threshold — so you're never caught off guard. Join the waitlist.