If your business is a federal corporation, search its name to find its business number, the first nine digits of its GST/HST number. Whether you are registered for GST/HST is in your CRA account, not on any public register.
In short
- Your GST/HST number is your nine-digit business number (BN), the letters RT and a four-digit reference number, such as 123456789 RT 0001.
- In your CRA account, choose your business account, then GST/HST: the account is listed by its RT number.
- The four-digit GST/HST access code is a different thing, used only for some ways of filing a return.
- You have a GST/HST number only once you register for the GST/HST, which most businesses must do when taxable sales pass $30,000.
Where to find my GST number in my CRA account
Sign in to your CRA account
Choose your business account, then GST/HST. Your GST/HST account is a CRA program account, listed by its RT number: your business number, RT and four digits.
Check your registration papers
The confirmation you saved or printed when you registered online shows it; Business Registration Online does not send it to you. If you registered by mail, or through British Columbia or Ontario, the CRA mailed a notice to confirm your accounts.
Look at your invoices
If you already charge the GST/HST, your number should be on your invoices: a registered supplier must show it on any invoice of $100 or more, so that customers can claim an input tax credit.
Find your business number
If you know only your business number, your GST/HST number is that BN, RT and four digits. The CRA's list of ways to find a business number, and the Business Enquiries line at 1-800-959-5525 (Monday to Friday, 8 a.m. to 8 p.m. Eastern), help with the rest.
What your GST/HST number looks like on an invoice
GST/HST stands for the goods and services tax and the harmonized sales tax. The CRA describes the GST/HST account number as the nine-digit business number that identifies the business, the two-letter program identifier RT for the GST/HST program, and a four-digit number for the specific account, for example 123456789 RT 0001. Most businesses have one GST/HST account, written RT0001 after the first nine digits.
A customer can confirm your number in the CRA's GST/HST Registry with the first nine digits, your business name or trade name as your invoice shows it, and the invoice date, so put the same name on your invoices.
The 15-character number that Corporations Canada's federal search shows for a corporation, such as 123456789RC0001, is its corporation income tax (RC) account: same first nine digits, different account. Find a federal corporation's business number with the business number lookup.
GST/HST number, access code and web access code
The GST/HST access code is a four-digit security code, not your GST/HST number. You need it only to file a return through NETFILE outside your CRA account, through accounting software, or by TELEFILE; filing in your CRA account, through your bank or by mail does not need it. Since October 2025 the code is shown in your own CRA account, but not to a representative. Keep it private.
A web access code still exists, but it is for information returns and corporation income tax filing, not for the GST/HST.
When you need to register for a GST/HST number
Most businesses must register once their taxable sales pass $30,000, either in one calendar quarter or over four calendar quarters in a row. Passing it in one quarter ends small supplier status that day; passing it over four quarters ends it at the end of the following month. You then have 29 days to register. Taxi and commercial ride-sharing drivers must register even below $30,000, and any business that makes taxable sales may register sooner by choice.
Registration is done online through Business Registration Online, which since July 14, 2026 is reached through your CRA account, or by mailing form RC1 if you cannot register online. It adds an RT account to your business number, or gives you a business number if you did not have one. From then on you charge, collect and remit the GST/HST, administered by the CRA everywhere but Quebec.
In Quebec: your GST and QST number
If your business is located in Quebec, Revenu Québec administers the GST/HST for it, and your Quebec sales tax (QST) has its own number: ten digits, the letters TQ and four more digits.
Frequently asked questions
Where do I find my GST number in my CRA account?
Sign in, choose your business account, then GST/HST. The account is listed by its RT number, which is your GST/HST number: your nine-digit business number, RT and four digits.
Is my GST number the same as my business number?
Your GST/HST number starts with your business number. It adds RT and four digits, such as 123456789 RT 0001, once you register for the GST/HST.
What does a GST number look like?
Nine digits, the letters RT and four more digits, for example 123456789 RT 0001. The first nine digits are the business number.
What is the GST/HST access code?
A four-digit security code for some ways of filing a GST/HST return, such as NETFILE outside your CRA account. It is not your GST/HST number, and it is shown in your own CRA account.
At what point do I need a GST number?
Most businesses must register for the GST/HST once taxable sales pass $30,000 in one calendar quarter or over four calendar quarters in a row. Taxi and ride-sharing drivers must register from the start.
Where do I find my QST number?
Revenu Québec gives the QST number when a business registers for the QST. It is ten digits, the letters TQ and four more digits.
Official sources
- Get a GST/HST access code(opens in a new tab)
Where the GST/HST account appears in your CRA account, and what the access code is for.
- General information for GST/HST registrants (RC4022)(opens in a new tab)
What a GST/HST account number looks like.
- Ways to find an existing business number(opens in a new tab)
The CRA's list of places to find your business number.
- When to register for and start charging the GST/HST(opens in a new tab)
The $30,000 small supplier threshold and who must register.
- Register as a resident with a Canadian business(opens in a new tab)
Business Registration Online, and registering by mail.
- Validating a QST registration number(opens in a new tab)
What a QST registration number looks like, from Revenu Québec.
This page explains the general rules. It is not tax or legal advice for a particular situation. The Canada Revenue Agency's and Corporations Canada's own pages are the official word; this page was last checked against them on Oct 28, 2026.