How to Register a Sole Proprietorship and Get a GST/HST Number in Canada
Start a one-person business the simple way: provincial business-name registration, CRA business number, and exactly when the $30,000 GST/HST rule kicks in.
How to Find Your Own GST/HST Number in Canada
Find your own GST/HST number in Canada: where it appears in My Business Account, which CRA documents carry it, what to do when you cannot sign in, and why the public registry cannot recover it for you.
Applies in: across Canada
The short answer
Your own GST/HST number lives in two places: your CRA documents, and My Business Account. It is the full 15-character account number, the 9-digit business number plus RT plus a four-digit reference number, and it appears on CRA notices, filed GST/HST returns, and remittance vouchers, and on the GST/HST tile in My Business Account. The public GST/HST Registry will not give it back to you, because that tool checks a supplier number against a name and a date. It is a verification tool for someone else's number, not a recovery tool for your own. Start with your own papers, then the online account, then the CRA phone line, in that order, and do not register for a new account because you cannot find the number. A business has only one business number, and a second registration creates a duplicate that has to be untangled.
Step 1: Check your own papers before you log in anywhere
The fastest route is usually a drawer, a filing cabinet, or an email folder, not a portal. Your GST/HST number appears on the documents the CRA issues for that account: notices of assessment for GST/HST, the personalized GST/HST return forms the CRA sends, filed returns and their confirmations, and remittance vouchers for the account. It also appears on the confirmation page saved or printed at the end of a Business Registration Online session, and in incorporation or provincial registration packages where a business number and program accounts were assigned automatically.
Search for the full 15-character form, not just nine digits. A document that shows only the 9-digit business number has not given you the GST/HST number yet. You need the RT letters and the reference number as well, and where a business holds more than one GST/HST account, you need the reference number for the right branch or division. If you find an old invoice you issued, check it too: a GST/HST registrant invoice shows the registration number, and the number you printed there is the number you were using at the time, provided the invoice has not been superseded by a later account change.
Step 2: Sign in to My Business Account and read the overview page
If your papers do not settle it, sign in to your CRA account and open My Business Account. The overview page is designed to answer exactly this question. The legal name that appears on your business number registration records and the 9-digit business number are both displayed at the top right of the overview page, and the business number is also displayed at the top of the left menu in the business number drop-down.
The program accounts sit in the centre column, under the Accounts heading, where a tile is displayed for each program account type associated with the business number. Choose the account link, for example RT0001, to open the GST/HST program account overview. The left menu lists the same accounts: expand GST/HST and select the program account you want. Either route shows the full account number for that account. Copy all 15 characters, including the RT letters and the reference number, and check that the business name beside it is the business you meant.
Step 3: Select the right business and the right account
Two selection mistakes cause most wrong-number problems. The first is the wrong business number. If you have more than one business number added in My Business Account, you select another from the drop-down options at the top of the left menu, and the information displayed on the overview page corresponds to the business number you select. A payroll account shown as RP0001 under one business number is a different account from RP0001 under another, and the same holds for RT accounts. Confirm the selected business number matches the business whose number you need before you copy anything.
The second is the wrong reference number. When you choose a program account type in the left menu, all your program accounts of that type are listed in a drop-down menu. A business with two GST/HST accounts lists RT0001 and RT0002, and you select the one whose returns, balances, and correspondence match the matter in front of you. If you are unsure which reference number a particular invoice or contract used, check the filed return or notice for that period rather than guessing. The reference number is part of the number, not a serial detail you can leave off.
Step 4: Do not use the public registry to recover your own number
The CRA GST/HST Registry is the wrong tool for this job, and using it wastes the one minute it is good at. The registry confirms whether a GST/HST account number was registered for a specific business name on a specific date. It asks for the first nine digits of the number, the exact registered business name, and the transaction date, and it answers for that combination. It does not accept a name alone, it does not list accounts, and it cannot return a number you do not already hold.
That distinction matters because the two jobs look alike from the outside. Checking a supplier number before you claim input tax credits is the registry job, and it is covered in the guide on looking up a GST/HST number. Recovering your own number is an account-access job, and it runs through My Business Account, your own documents, or the CRA phone line. If someone tells you to recover your own number from the registry, they have confused the two jobs.
There is also no public business number directory to fall back on. The registry is the only public number check the CRA offers, and it is a supplier check. Your own numbers are private account information, and the CRA releases them only through authenticated channels: your online account, documents already issued to you, or an identity-verified phone call.
Step 5: Call the CRA when the other routes fail
If no document exists anywhere and you cannot sign in, call the CRA Business Enquiries line at 1-800-959-5525. Identity verification is required before an agent confirms a number, so gather what you have before you call: the business legal name and any operating name, the business addresses on file, the names of owners or directors, and any CRA document, however old, that shows part of the number or the business name as registered. An agent can confirm the business number and the program accounts attached to it once identity is established.
Do not apply for a new business number or a new GST/HST account simply because the old number cannot be found. The CRA states that a business or legal entity can have only one business number, and registering again creates a duplicate root with its own accounts, filings, and balances. If an online registration session ended unexpectedly, or an incorporation package never arrived, tell the CRA that when you call, so the existing registration can be located rather than replaced. If you have an authorized representative, such as an accountant with Represent a Client access, ask them as well: a representative with access to the business account can read the full account numbers from the same overview page, and that is often faster than the phone queue.
Once the number is recovered, write it down where the business records live, with the reference number and the business name it belongs to, and save the My Business Account confirmation or the notice that shows it. The next time the number is needed, for an invoice, a supplier form, a bank form, or a return, the answer should be a lookup in your own records, not another search.
What not to do
- Do not give a supplier, a customer, or a bank only the 9-digit business number when they ask for your GST/HST number. The RT letters and reference number are part of the number.
- Do not use the GST/HST Registry to recover your own number, and do not treat a registry no-match for your own details as proof the account does not exist.
- Do not register for a new business number or GST/HST account because the old one cannot be found.
- Do not copy a number from an old invoice without checking whether the account or reference number has changed since that invoice was issued.
- Do not share the number, or any CRA account detail, through an unverified caller or website that claims to look it up for you. The CRA releases account numbers through its own authenticated channels only.
Related guides:
Recovering your own GST/HST number, in five steps
- Check your own papers firstLook at CRA notices, filed GST/HST returns, and remittance vouchers. The full GST/HST account number appears on the documents for that account.
- Sign in to My Business AccountThe overview page shows the business name and 9-digit business number, and each program account tile carries its full number, such as RT0001.
- Select the right business and accountIf more than one business number or GST/HST account is listed, select the one that matches the business and branch you need the number for.
- Copy the full 15 charactersCopy the business number, the RT letters, and the four-digit reference number together. A supplier, a bank, or a form that asks for your GST/HST number needs the whole account number.
- Call the CRA if nothing worksIf no document exists and you cannot sign in, call Business Enquiries at 1-800-959-5525. Identity verification is required before the CRA confirms a number.
Questions people ask
Where do I find my GST/HST number?
On your own CRA documents and in My Business Account. The full number appears on CRA notices of assessment, filed GST/HST returns, and remittance vouchers for the account, and in My Business Account the GST/HST program account tile shows the full number, such as 123456789RT0001. The 9-digit business number alone is not the GST/HST number; the RT letters and the four-digit reference number are part of it.
How do I find my GST/HST number in My Business Account?
Sign in to your CRA account and open My Business Account. The overview page displays the legal name and the 9-digit business number at the top right, and the program account tiles in the centre column show each account with its full number. Choose the GST/HST tile, for example RT0001, to open that account. If you have more than one business number added, select the right one from the business number drop-down first, because the page shows the accounts for the selected business number only.
Can I look up my own GST/HST number in the CRA GST/HST Registry?
No. The GST/HST Registry is built to check a supplier number, not to recover your own. It needs the first nine digits of the supplier account number, the supplier exact registered business name, and a transaction date, and it answers whether that combination was valid on that date. It does not list your accounts, and entering your own details there will not return your number. Use My Business Account, your CRA documents, or the Business Enquiries line instead.
I lost my GST/HST number and cannot sign in. What do I do?
Search your own records first: CRA letters and notices, filed returns, remittance vouchers, incorporation or provincial registration packages, and any confirmation page saved when the account was registered. If nothing turns up, call the CRA Business Enquiries line at 1-800-959-5525. The CRA will verify your identity before confirming the number, so have the business legal name, addresses, and any document you do hold ready before you call.
Is my GST/HST number the same as my business number?
No. Your business number is the 9-digit root identifier for the business. Your GST/HST number is that root plus the RT program identifier and a four-digit reference number, for a total of 15 characters, usually written 123456789RT0001. The same business number can carry other program accounts, such as RP for payroll and RC for corporation income tax, each with its own reference number.
What if I have more than one GST/HST account?
Use the reference number that matches the branch or division you are dealing with. A business with two GST/HST accounts holds RT0001 and RT0002 under the same business number, and My Business Account lists each separately. Check the notice, return, or invoice in front of you, and give the full number for that account, because a payment or filing under the wrong reference number does not clear the obligation on the right one.
Sources
- CRA — My Business Account overview (Canada.ca) — the overview page shows the legal name and 9-digit business number at the top right, program account tiles in the centre column, and how to select between multiple business numbers and multiple accounts of the same type.
- CRA — Confirming a GST/HST account number (Canada.ca) — the registry confirms that the business charging GST/HST is registered, needs the first nine digits, the business name, and the transaction date, and exists so input tax credit claims cover only tax charged by a registered supplier.
- CRA — Confirming a GST/HST account number: terms and conditions of use (Canada.ca) — the registry is not a search engine and is to be used only to validate the GST/HST number of a business.
- CRA — When you need a BN (Canada.ca) — a business can only have one business number for the same business or legal entity; newly registered program accounts are added to the existing number.
- CRA — Businesses: Go online to register for a business number or CRA program account (Canada.ca) — new business number and program account registrations must be done online through Business Registration Online since November 3, 2025; a business number is a 9-digit number and a GST/HST account is that number plus RT plus a four-digit reference number.