To register for a GST/HST number in Canada, sign in to your CRA account and use Business Registration Online (BRO) — it is the fastest route, and since 3 November 2025 the CRA no longer accepts registrations by phone. If you cannot register online, mail Form RC1, Request for a Business Number and Certain Program Accounts, to your tax centre. Registration is free. You will receive a 9-digit Business Number (BN) if you do not already have one, and a GST/HST account number made up of your BN plus “RT” and a four-digit reference — for example, 123456789RT0001. You must register once your taxable sales pass $30,000 in a single calendar quarter or over four consecutive quarters, and you have 29 days from that point to complete the registration. This guide walks through the threshold, what to have ready, the online steps, and what to do once your number arrives.
What Is a GST/HST Number?
A GST/HST number is the account number the Canada Revenue Agency (CRA) gives your business so you can charge, collect and remit the Goods and Services Tax (GST) or Harmonized Sales Tax (HST) — and claim input tax credits (ITCs) on the GST/HST you pay on business purchases.
The number has three parts:
- Your 9-digit Business Number (BN) — the CRA’s single identifier for your business, used across all its program accounts.
- The program identifier “RT” — the letters that mark the account as a GST/HST account.
- A 4-digit reference number, usually 0001 for your first GST/HST account.
So a typical GST/HST number looks like 123456789RT0001. If your business later opens a separate GST/HST account for a branch or division, the reference number changes (RT0002, and so on). If you already have a BN from an earlier registration — for example, a payroll deductions account — the CRA attaches the RT account to that same BN instead of issuing a new one.
The rates you will charge once registered are 5% GST in provinces without HST, and HST of 13% in Ontario, 15% in New Brunswick, Newfoundland and Labrador and Prince Edward Island, and 14% in Nova Scotia (since 1 April 2025). Which rate applies depends on the place of supply — generally where the goods are delivered or the services performed — not on where your business is located.
Do You Have to Register? The $30,000 Small Supplier Threshold
You must register for GST/HST once you stop being a “small supplier.” A small supplier is a business whose worldwide taxable supplies — including zero-rated supplies, and including the taxable supplies of its associates — do not exceed $30,000. The CRA tests that figure two ways, and tripping either one ends your small-supplier status:
| Test | You stop being a small supplier | Start charging GST/HST | Register within |
|---|---|---|---|
| Over $30,000 in a single calendar quarter | The day of the sale that pushes you past $30,000 | On that same sale | 29 days of that day |
| Over $30,000 across four consecutive calendar quarters (but never in one quarter) | The end of the month after the quarter in which you crossed $30,000 | Your first sale after that month | 29 days of the effective date |
A few points that catch new business owners out:
- The $30,000 is gross revenue, not profit. It is your total taxable sales before expenses, and it counts sales worldwide, not just Canadian sales. Exempt supplies, financial services, sales of capital property and goodwill from the sale of the business are left out of the count.
- The four-quarter test is rolling. Any four consecutive calendar quarters count — not just the calendar year. Track your sales quarterly so the crossing does not surprise you.
- The 29-day clock starts on your effective date of registration, which is usually the day you stopped being a small supplier. If you were required to register — or were already charging GST/HST — for more than 30 days before registering, the CRA has a separate backdating process.
- Charities and public service bodies use a $50,000 threshold instead of $30,000.
- Taxi operators and commercial ride-share drivers must register from their very first fare, whatever they earn. There is no small-supplier threshold for them.
If you only make exempt supplies — music lessons and tutoring are the CRA’s own examples — you do not need to register at all, because you cannot charge GST/HST on exempt supplies in the first place.
Should You Register Voluntarily?
You can register voluntarily even while you are still a small supplier, and for many new businesses it is the right move. The main reason is input tax credits: once registered, you can claim back the GST/HST you pay on business purchases — software, equipment, rent, professional fees — which unregistered small suppliers cannot do. If your start-up costs are high relative to your sales, voluntary registration can put real money back in your pocket.
It also looks more professional. Some larger customers and government buyers prefer dealing with GST/HST-registered suppliers, and having a GST/HST number on your invoices removes a common friction point in B2B work.
Two things to weigh before you register voluntarily:
- Your effective date is usually the date of your request, though it can be backdated up to 30 days. From that date you must charge GST/HST on your taxable sales and file returns — even nil returns in periods with no sales.
- You may need to stay registered for at least one year before you can cancel your registration. Voluntary registration is not something to switch on and off month to month.
If you are just starting out and do not know your first-year revenue, the CRA lets a new business give a reasonable estimate of its income for the year. Register when the numbers justify it — and if you expect to cross $30,000 quickly, register before you get there rather than scrambling inside the 29-day window.
What You Need Before You Register
Registration goes quickly if you gather the information first — especially online, where the CRA’s session times out after 10 minutes of inactivity and you cannot save partway through. Have the following ready:
About you (the person submitting the registration):
- Last name, Social Insurance Number (SIN) and date of birth
- Postal code of your home address
About your business:
- Business name, and your Business Number if you already have one
- Type of business — sole proprietorship, partnership, corporation, trust, and so on
- Names and SINs of all owners
- Physical and mailing addresses
- A description of your major business activity
- Your fiscal year for GST/HST — usually the same as your tax year for income tax purposes (the calendar year for most individuals and sole proprietors)
- Your total annual revenue, including taxable sales of all your associates — a reasonable estimate is fine for a new business
- Your effective date of registration (see the threshold section above)
One special case: if you are a sole proprietor with a temporary SIN starting with 9, you must register through Business Registration Online. Directors, partners and trustees with a temporary SIN starting with 9 cannot use BRO for a GST/HST account — they must use Form RC1 by mail instead.
How to Register for a GST/HST Number in Canada — Step by Step
Step 1: Sign in to your CRA account
Since 14 July 2026, Business Registration Online (BRO) is only available through your CRA account — sign in first, then look for Business Registration Online. You cannot create a CRA account if you have not filed your taxes, or if you have enhanced protection enabled on your account. If you are a business owner, select Add account, then Business account, then Business Registration Online.
Step 2: Choose what to register
Select Register a business and follow the prompts. If you do not have a Business Number yet, the CRA issues one during the same session. Then choose Register an RT account for your GST/HST account. You can register other program accounts in the same session — for example, a payroll deductions (RP) account if you have employees. Our guide to CRA payroll deductions in Canada explains what that account covers and what you must deduct and remit once it is open.
Step 3: Enter your business details
Work through the screens with the information from the checklist above: business name and type, owners, addresses, major business activity, fiscal year, annual revenue and your effective date of registration. For a new business, enter your best estimate of annual revenue — the CRA accepts a reasonable estimate.
Step 4: Save your numbers before you close the session
This is the step people miss. Save or print your Business Number and GST/HST account number during your online session — the CRA will not send them to you afterwards. Your BRO session times out after 10 minutes of inactivity and you cannot save your progress, so do not start the process until you have your documents in hand. Residents of Ontario and Nova Scotia can link directly from BRO to the provincial registration site.
If you cannot register online: mail Form RC1
If BRO is not an option for you — for example, a business owned by another business, a business with only non-resident owners, or an estate registering for a deceased owner — complete Form RC1, Request for a Business Number and Certain Program Accounts, and mail it to your tax centre. Form RC1 covers the BN and the GST/HST (RT), payroll deductions (RP), corporation income tax (RC), registered charity (RR) and information returns (RZ) accounts on a single form. Allow extra time: mailed registrations take longer than online ones, and you cannot charge GST/HST until your registration is effective.
If your business is in Quebec
Businesses physically located in Quebec register with Revenu Québec, not the CRA — the GST/HST and the Quebec Sales Tax (QST) are administered together there. The small-supplier test is the same $30,000. Use Revenu Québec’s Register a New Business service, or form LM-1-V if you are registering by paper.
Do not register by phone
The CRA stopped accepting Business Number and program account registrations by phone on 3 November 2025. Any older guide that lists a phone number for GST/HST registration is out of date — online through BRO, or Form RC1 by mail, are the routes now.
How to Read Your GST/HST Number — and Check Someone Else’s
Your GST/HST number is your 9-digit Business Number, followed by RT, followed by a four-digit reference — 123456789RT0001 for a first account. Quote the full number on your invoices: customers who are themselves GST/HST registrants need it to claim input tax credits on what they buy from you, and a missing or wrong number is a common reason an ITC claim gets questioned.
Before you claim input tax credits on a supplier’s invoice, you can check that the supplier’s GST/HST number is valid. The CRA runs a free GST/HST Registry for exactly that purpose — enter the supplier’s number and it confirms whether the account is registered. It takes a minute, and it protects you if the CRA ever reviews your ITC claims.
What to Do After You Register
Registration is the start of the obligations, not the end of them. As a GST/HST registrant you must:
- Add your Business Number to your CRA account so you can access and manage your program accounts online.
- Charge and collect GST/HST on your taxable supplies from your effective date of registration — at the rate for the province where the supply is made.
- File a GST/HST return for every reporting period, even if you had no sales. A nil return is still a return, and skipping it is one of the most common compliance mistakes new registrants make. Our step-by-step GST/HST return guide walks through who files, the reporting periods, the deadlines and how to file online with GST/HST NETFILE.
- Remit the tax you collected, less the input tax credits you claim. Your reporting period — annual, quarterly or monthly — is assigned by the CRA based on your annual taxable supplies: $1,500,000 or less files annually, over $1,500,000 up to $6,000,000 files quarterly, and over $6,000,000 files monthly.
- Keep your records. Invoices, receipts and the workings behind every return should be kept for six years, and your GST/HST number should appear on every invoice you issue.
If your business grows or your circumstances change — a new branch in another province, a change of fiscal year, closing the account — tell the CRA promptly. A GST/HST account that no longer matches how the business actually operates is how penalties start.
5 Mistakes to Avoid When Registering for a GST/HST Number
1. Charging GST/HST before your effective date. You cannot collect tax before you are registered. Charge only from your effective date of registration — and on the single-quarter test, remember that date can be the very sale that pushed you over $30,000.
2. Missing the 29-day window. Once you stop being a small supplier you have 29 days to register. Mark the date the moment your sales cross the threshold; late registration can mean penalties and interest.
3. Forgetting nil returns. Registering creates a filing obligation for every reporting period, including periods with zero sales. File the nil return — it takes minutes online and keeps your account in good standing.
4. Treating the Business Number and the GST/HST number as the same thing. The BN is the 9-digit identifier; your GST/HST number is the BN plus RT plus the reference (RT0001). Suppliers, customers and the CRA all need the full number.
5. Registering with the wrong authority in Quebec. If your business is physically located in Quebec, register with Revenu Québec. A CRA registration alone does not cover you there.
Frequently Asked Questions
How long does it take to get a GST/HST number in Canada?
Online registration through Business Registration Online is the fastest route — most businesses complete it in one session of about 15 to 20 minutes and receive their Business Number and GST/HST account number immediately. Registration by mail with Form RC1 takes longer, because the CRA must process the paper form. Registration itself is free either way.
Do I need a GST/HST number if I earn less than $30,000?
No — if your taxable supplies are $30,000 or less in a single calendar quarter and over the last four consecutive quarters, you are a small supplier and registration is optional. You may still register voluntarily, which lets you claim input tax credits on your business purchases. Once you cross $30,000, registration becomes mandatory and you have 29 days to register.
Can I register for a GST/HST number before I start my business?
Yes. A new business can register voluntarily before making its first sale, and the CRA accepts a reasonable estimate of first-year revenue for a new business. Voluntary registration is usually effective from the date of your request, and you may need to stay registered for at least one year before cancelling.
Is a GST/HST number the same as a Business Number?
No, but they are linked. Your Business Number is a 9-digit identifier for your business with the CRA. Your GST/HST number is that Business Number plus the program identifier RT and a four-digit reference — for example, 123456789RT0001. If you already have a BN, the CRA adds the RT account to it when you register for GST/HST.
Can I register for a GST/HST number by phone?
No. The CRA stopped accepting Business Number and CRA program account registrations by phone on 3 November 2025. Register online through Business Registration Online (via your CRA account) or by mail with Form RC1. Any guide that still lists a phone number for registration is out of date.
How do I check if a GST/HST number is valid?
Use the CRA’s free GST/HST Registry. Enter the supplier’s full GST/HST number and the registry confirms whether the account is registered. Checking before you claim input tax credits protects you if the CRA reviews your claims.
If registering for GST/HST is your first step into running a Canadian business, the next step is learning to do the tax work properly — filing the returns, claiming the credits, and keeping the records the CRA expects. Get Trained Get Hired’s GST/HST Course in Mississauga covers GST/HST from registration through filing, with hands-on practice on real scenarios instead of theory alone. Learn more about the GST/HST Course in Mississauga or call (647) 276-7150 to speak with an advisor.
