HST Registration
in Ontario
New Businesses & Sole Proprietors
The Line Is $30,000.
Crossing It Is the Easy Part.
Every business in Ontario that sells something taxable has an HST question waiting for it, and most people meet it late, after the line has been crossed and the tax they should have been charging has quietly become tax they owe. This guide covers when registration stops being optional, which day you have to start charging 13% from, how to get the number, what you can claim back, and the simplified method that suits a lot of small service businesses. It's general information. We handle the registration and the returns as part of bookkeeping.
Two Ways to Cross the Line
While your taxable sales stay at or under $30,000 you are a small supplier, and you do not have to register. The test is not the calendar year. It runs over four consecutive calendar quarters, so a business that did $8,000 in each of the last four quarters is sitting at $32,000 and is over, whatever its year-end says. Watch the rolling total, not the tax year.
Cross it slowly, over four quarters or fewer without any single quarter doing it alone, and you stop being a small supplier at the end of the month following the quarter in which you went over. Your effective date of registration is no later than the day of your first sale after that, and you have 29 days from that effective date to register.
Cross it fast, with more than $30,000 in a single calendar quarter, and there is no grace month. You stop being a small supplier on the sale that took you over, and that sale carries HST. Your effective date is no later than that day, and again you have 29 days from it to register. A big contract in a quiet year does this to people who were nowhere near the line in any other quarter.
Charging From the Right Day
You charge HST on your taxable sales from your effective date of registration, which, as above, is set by when you crossed and not by when you got around to the paperwork. Tax you were required to collect and did not is still owed to the CRA, and it comes out of your own margin. If you crossed in March and registered in August, the sales in between are HST-inclusive whether you billed it or not.
The rate depends on the place of supply. A sale to a customer in Ontario carries 13% HST. A sale delivered into a province that has only the GST carries 5%, and the other HST provinces have their own rates. For a London business selling locally that is one number, 13%, on every invoice.
Your invoices have to carry your registration number once you have one. It is also what lets your business customers claim the tax back: on a purchase of $100 or more, the supplier's registration number is one of the things the CRA requires on the receipt before the credit can be claimed, so a missing number costs your customer money and gets noticed.
Registering Before You Have To
A small supplier may register voluntarily. The effective date is usually the day you ask, and can be set up to 30 days earlier, and you may need to stay registered for at least a year before you can cancel. The reason to do it is the credits: once registered, the HST on what you buy for the business comes back to you, and a start-up spending on equipment, software, and a vehicle before it has much revenue can have a lot of it to recover.
The reason not to is your customers. A registered business charges 13% to everyone. A business customer claims it back and does not care; a household customer pays it and does, so a service sold to the public gets 13% more expensive on the day you register, with nothing to show for it. Which side of that line your customers sit on is usually the whole decision.
One business has no choice and no threshold. If you drive a taxi or commercial ride-share, you register from the day you start carrying passengers, small supplier or not.
Getting the Number
HST registration is a program account, the RT account, attached to a business number. A sole proprietor only needs a business number when they register for a program account, so for most this is the moment they get one. Both come through Business Registration Online, and since November 3, 2025 that is the only route: registrations for a new business number or program account are done online, behind a CRA account sign-in, and a call to the business line sends you back to the portal.
So the sign-in has to exist first. If you do not yet have a CRA account, identity verification by mailed security code can take the better part of two weeks, and that is time the 29 days do not stop for. Our CRA account guide covers setting it up. If a payroll account or a corporation account is coming too, the same session registers all of them.
What You Can Claim Back
A registrant recovers the GST/HST paid on purchases and expenses used in the business through input tax credits, claimed on the return against the tax collected. The supplies, the laptop, the accountant's invoice, the business share of the phone: the 13% on each comes back, which is why registration is often worth it before the threshold and always worth doing properly after.
Two things govern it. The receipt has to carry what the CRA requires for its size: under $100 the basics, from $100 the supplier's registration number, and from $500 the purchaser's name and a description as well. And there is a clock. For most registrants a credit has to be claimed by the due date of the return for the last reporting period that ends within four years of the period in which it first became available; a few large businesses and financial institutions get two.
What does not come back is the HST on anything personal, or on the personal share of something mixed, and the credits on a home office or a vehicle follow the same percentages the income tax deductions do.
Filing, Paying, and the Quick Method
Most new small businesses file once a year, and can choose quarterly or monthly instead. Monthly and quarterly filers have one month after the end of the period to file and pay. Annual filers have three months after their fiscal year-end, with one exception that catches sole proprietors: an individual with business income and a December 31 year-end files by June 15 but pays by April 30, the same split as the income tax return, and interest runs from May 1 on anything unpaid.
The quick method is the simplification worth knowing about. A business whose annual taxable sales, HST included, are $400,000 or less can elect it. You still charge 13%, but instead of tracking the credit on every purchase, you remit a flat share of your sales: for an Ontario business providing services, 8.8%; for one buying goods for resale, where those goods are at least 40% of sales, 4.4%; with a 1% credit on the first $30,000 of eligible sales each year. The difference between the 13% collected and the share remitted is yours, in place of the credits you give up on day-to-day purchases.
For a service business with few taxable inputs, a consultant, a tradesperson who supplies labour, the quick method usually comes out ahead and is far less work. For one with heavy purchases, the credits are worth more than the flat rate saves. It is a calculation we run before choosing, because the election binds you for at least a year.
Common Questions
Three Things People Ask
Do I have to charge HST if I make under $30,000?
No. At or under $30,000 of taxable sales over four consecutive calendar quarters you are a small supplier, and registration is optional. The exception is taxi and ride-share driving, which registers from the first fare. Many businesses under the line still register voluntarily, because it lets them claim the HST on what they buy back; the cost is that every customer then pays 13% more.
I crossed $30,000 months ago and never registered. What now?
Register now, with the effective date the rules set, which is the day you stopped being a small supplier, not today. The HST on every taxable sale since then is owed, whether or not you billed it, and comes out of what you were paid. The credits on what you bought in the same period come back against it, which softens the bill. Waiting makes the number bigger and adds interest; it does not make it go away.
Can I get back the HST on what I buy for the business?
Once registered, yes, through input tax credits claimed on your return against the tax you collected. The receipt has to carry the supplier's registration number for anything of $100 or more, and most registrants have four years to claim. Personal purchases and the personal share of mixed ones do not qualify. Under the quick method you give those credits up on day-to-day purchases in exchange for remitting a flat share of sales.
Sources: CRA, When to register for and start charging the GST/HST · CRA, Register for a GST/HST account · CRA, Charge and collect the GST/HST · CRA, Input tax credits · CRA, Reporting requirements and deadlines – File your GST/HST return · CRA, Quick Method of Accounting for GST/HST · CRA, Businesses: Go online to register for a business number or CRA program account · CRA, When you need a BN
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