GST/HST Registration: When Do You Need It?

Imagine you are a freelance designer in Toronto. Business is good — $8,000 a month in client work. Then one month you land a big project, and suddenly your rolling 12-month revenue hits $31,000. Congratulations! You are now legally required to collect and remit GST/HST. If nobody told you that, you might keep invoicing without tax for months — and the CRA will still expect you to pay the tax you should have collected, out of your own pocket. Ouch.

Canada's magic number for GST/HST is $30,000. Cross it, and the government politely insists you join the tax-collecting team. Here is how the threshold actually works.

• What counts toward the $30,000? Your total taxable supplies (sales of goods and services subject to GST/HST) over the previous four consecutive calendar quarters. Exempt supplies — like most health care services or basic groceries — do not count. Financial services and some other categories are excluded too, so the number that matters is your taxable revenue, not every dollar that touched your account.
• When does the clock start? It is a rolling 4-quarter window, not a calendar year. The moment you exceed $30,000, you are considered a "registrant" — you must register within 29 days of the end of the quarter in which you crossed the line, and start charging GST/HST on your next supply. Miss the deadline and you owe the tax anyway, plus potential penalties. This is why watching the number monthly matters more than watching it yearly.
• What rate do you charge? It depends on where your customer is, not where you are. Ontario customers: 13% HST. Alberta: 5% GST. British Columbia: 5% GST (plus PST rules on top, which is a whole separate adventure). If you sell across provinces, your invoicing needs to know the map. The CRA's place-of-supply rules decide which rate applies.
• Why register early, voluntarily? Because registration lets you claim input tax credits (ITCs) — you get back the GST/HST you pay on business expenses. Say you buy a $2,000 laptop plus $260 HST for the business. As a registrant, that $260 comes back to you as a credit against the tax you collected. Without registration, it is just gone. Voluntary registration makes sense when your clients are mostly businesses (they recover the tax themselves, so they do not care about the extra line on your invoice) and your expenses are significant.
• What happens after you register? You charge the tax on every taxable invoice, file GST/HST returns (annually, quarterly, or monthly depending on your revenue — most small businesses file annually), and remit the difference between tax collected and ITCs claimed. Keep every receipt: ITCs require documentation, and "I lost the receipt" is not a recognized tax credit.

A quick decision checklist for voluntary registration: Are most of your clients GST/HST registrants themselves? Do you spend meaningfully on taxable business inputs — equipment, software, subcontractors, rent? Is your revenue approaching $30,000 anyway, so registration is coming regardless? Three yeses means registering early is probably smart. Mostly consumers as clients and tiny expenses? Waiting is reasonable — but keep watching that rolling total.