Registering for the GST/HST in Canada: when you must, how to do it, and what changes the day after

For most new businesses in Canada, the GST/HST arrives as a single number: $30,000. Stay under it and you do not have to register; go over it and you do. What is less clear is what registering involves and how much it changes the way you invoice, keep records and file.

This note walks through it in order. Everything here comes from Canada Revenue Agency pages listed at the end, checked on 1 October 2026. It is general information for a sole proprietor or small business, not tax advice; an accountant can tell you how it applies to you.

When you have to register

You are a small supplier, and do not have to register, while your taxable sales stay at or under $30,000. For a sole proprietor the CRA counts revenue before expenses from all your taxable supplies worldwide, across all your businesses and those of your associates. It excludes financial services, sales of capital property and goodwill from the sale of a business.

There are two ways to cross the line, and they set different start dates:

In a single calendar quarter. You must charge the GST/HST on the very sale that took you over $30,000. Your registration is effective no later than the day of that sale.
Over four consecutive quarters, but not in any one quarter. You stop being a small supplier at the end of the month following the quarter in which you crossed it, and your registration is effective no later than your first sale after that.

Either way, you have 29 days from your effective date to register. Taxi and ride-sharing drivers are the main exception: they must register even if they are small suppliers.

You can also register voluntarily before you reach the threshold, if you make taxable supplies. The CRA sets out the trade: once registered, you must charge, collect and remit the tax and file returns, and you must stay registered for at least one year before you can cancel (unless you stop your business). In return, you can claim input tax credits on what you spend. If you do not register, you do not charge the tax and you cannot claim credits. You generally cannot register if you provide only exempt supplies.

How to register

Online, through Business Registration Online (BRO). The CRA calls this the fastest and easiest way. You need a CRA account to use it. If you do not already have a business number, you get one at the same time as your GST/HST account. Save or print your business number at the end, because the CRA says it will not be sent to you, and note that the session times out after 10 minutes of inactivity, so have your details ready before you start.

By mail, with Form RC1. If you cannot complete registration online, the CRA's instructions are to mail Form RC1, Request for a Business Number and Certain Program Accounts, to your tax centre.

What you get is a nine-digit business number (BN), with a GST/HST program account added to it. That account number is what goes on your invoices.

What changes after you register

1. You charge the right rate for the place of supply

The rate depends on where the supply is made, not where you are. In Ontario the HST is 13 per cent. The CRA's calculator lists the other rates: 15 per cent in New Brunswick, Newfoundland and Labrador and Prince Edward Island; 14 per cent in Nova Scotia; and the 5 per cent GST alone in Alberta, the three territories, and the provinces that run their own sales tax (British Columbia, Manitoba, Saskatchewan and Quebec), where provincial tax is separate. If you sell into other provinces, check the place-of-supply rules first.

2. Your invoices and receipts need more information

This works in both directions. To claim input tax credits, the CRA requires your supporting documents to carry more detail as the amount grows:

Amount of the purchase	What the document must show
Under $100	Supplier's name, date, total amount
$100 to $499.99	All of the above, plus the GST/HST charged (or a statement that it is included) and the supplier's GST/HST registration number
$500 or more	All of the above, plus the buyer's name, a brief description of the supply and the terms of payment

Your customers who are registrants will need the same from you. Put your GST/HST number on every invoice from your effective date.

3. You can claim input tax credits

An input tax credit (ITC) recovers the GST/HST you pay on purchases for your commercial activities. The time limit is generous but real: generally, an ITC must be claimed by the due date of the return for the last reporting period that ends within four years after the end of the period in which it first became available. New registrants can also claim credits on inventory and capital property they hold on the day they register.

4. You file on a schedule set by your sales

The CRA assigns a reporting period based on your annual taxable supplies:

Annual taxable supplies	Reporting period
$1,500,000 or less	Annual
More than $1,500,000, up to $6,000,000	Quarterly
More than $6,000,000	Monthly

You can ask for a more frequent period with Form GST20. Monthly and quarterly returns are due one month after the period ends. Annual returns are generally due three months after your fiscal year-end, with an exception for many sole proprietors: if your fiscal year ends on 31 December and you have business income, the return is due on June 15, but the payment is due on April 30. Electronic filing is mandatory for almost all registrants.

5. You may owe instalments

An annual filer whose net tax for the previous fiscal year was $3,000 or more may have to pay quarterly instalments, due within one month after the end of each fiscal quarter. Because the test looks at the previous year, it rarely applies in the first year after registering.

6. You file even when there is nothing to report

A registrant must file a return for every reporting period, even with no sales or no tax to remit. The CRA calls this a nil return. Set a reminder for quiet periods too.

The Quick Method: worth a look for service businesses

The CRA's Quick Method of accounting is an optional, simpler way to calculate what you remit. Instead of tracking the tax you collected minus your input tax credits, you remit a fixed percentage of your tax-included sales and claim credits only on capital purchases.

The key points from the CRA's guide, RC4058:

you are generally eligible if your annual worldwide taxable supplies, including GST/HST, are not more than $400,000; legal, accounting, bookkeeping and tax-preparation services are excluded;
for a service business with an Ontario location making supplies taxed at 13 per cent, the remittance rate is 8.8 per cent of tax-included sales;
you get a 1 per cent credit on the first $30,000 of eligible sales each year;
annual filers must elect by the first day of their second fiscal quarter, online or with Form GST74.

It tends to suit businesses with low taxable expenses; if you buy a lot of taxable materials, the regular method may come out ahead. Run both on last year's numbers before choosing.

Records, and how to stop

Keep your GST/HST records for six years from the end of the year they relate to.

If your sales fall back below the threshold, you can close the account, online through My Business Account or by mail with Form RC145, as long as you have been registered for at least one full year. You must file a final return, and on closing you are treated as having sold the inventory and capital property you hold, so GST/HST may be owed on them in that final return.

A checklist for the day you register

Write down your effective date and the 29-day deadline.
Save your business number and GST/HST account number.
Add the account number and the tax line to your invoice template.
Start keeping purchase receipts that meet the ITC rules in the table above.
Put your filing date, and the April 30 payment date if it applies, in your calendar.
Decide on the Quick Method before the election deadline.

Drafted with AI assistance.

Sources

Money
Taxes
Canada
Small business