A lot of solo craftsmen treat HST as something that kicks in once they feel established enough, the way you might decide you're "big enough" for a logo or a van wrap. It doesn't work that way. The CRA doesn't care how established you feel — it cares about one number, checked every quarter, and crossing it changes what you're legally allowed to write on an invoice the same day it happens.
The number is $30,000, and there are two ways to hit it
Below $30,000 in worldwide taxable revenue, you're what the CRA calls a "small supplier," and small suppliers are not required to register for or charge GST/HST. Above that line, you're not. There are two separate tests that can take you over it:
- The single-quarter test: if your revenue in any one calendar quarter goes over $30,000 on its own, your small-supplier status ends immediately — not at month-end, not at your next invoice, right then.
- The rolling four-quarter test: even if no single quarter crosses $30,000 by itself, the CRA also totals your revenue over the trailing four calendar quarters. Cross $30,000 on that rolling total and the same obligation applies.
Either way, once you're over, you have a short window to actually register — the CRA's own "when to register" guidance has the exact date that applies to your situation, since it depends on which test you crossed and when. Don't guess at the deadline; confirm it directly rather than assuming you have until your next slow month to deal with it.
The part that actually catches people: charging HST starts before your GST/HST number does
Registering is a process with a lead time. Being obligated to charge HST is not — it starts from the sale that pushed you over the threshold, whether or not your registration has gone through yet. That means there's a real gap where you owe HST on work you've already quoted at a price that didn't include it. The fix isn't to panic-raise your prices retroactively; it's to register the moment you see the threshold coming, not after you've already blown past it on a big job.
What changes on every quote and invoice after you register
Once you're registered, HST isn't optional on any taxable job, regardless of whether the client is a homeowner or another business. Your quotes need to show it as its own line, not folded into a single number — a client comparing your quote to someone else's small-supplier price will see a line item they didn't see before, and it's worth saying plainly that the law requires it rather than letting them assume you just raised your rate. You'll also need to start filing GST/HST returns on whatever period the CRA assigns you (usually annually or quarterly for a business your size), and remit what you collect, minus what you can claim back.
The upside most craftsmen don't think about: input tax credits
Registering isn't only a new cost to pass on. Once registered, you can claim back the HST you pay on materials, tools, fuel, and other business expenses through input tax credits (ITCs) — money that, as a small supplier, you were simply absorbing into your own cost every time you bought lumber or a new tool. For a craftsman who buys a meaningful amount of material per job, this is real money, not a rounding error, and it's the main reason some tradespeople register voluntarily well before $30,000 forces their hand.
The trade-off: voluntary registration means charging HST on every invoice from that point on, even to homeowner clients who'll simply see your price go up by 13% with no ITC of their own to offset it. Whether that's worth it depends on how much you spend on taxable materials and tools relative to how price-sensitive your typical client is — a real calculation worth doing with a bookkeeper, not a guess.
Keep your own number, don't wait for a client to ask
The clients and platforms you work with aren't tracking your rolling four-quarter revenue — that's entirely on you. A simple running total, checked at the end of every quarter, is the whole system. Catching it early means registering calmly and adjusting your quote template once; catching it late means an awkward conversation about why last month's invoice is suddenly missing a tax line it should have had.