What Is a Business Number in Canada? BN Explained
A business number (BN) is the unique nine-digit number the Canada Revenue Agency (CRA) uses to identify your business. You do not apply for it on its own. If your business is unincorporated, the CRA issues your BN the first time you register for a program account, such as GST/HST or payroll. Each program account then adds a two-letter code and a four-digit reference to that nine-digit root. This guide covers what the number is, how program accounts hang off it, whether a sole proprietor needs one, how it differs from a corporation number and your social insurance number, how to get one, and how to find a BN you have lost.
What a business number is
The business number is a standard identifier that lets you deal with the CRA and, through the same number, with many provincial, territorial, municipal, and other federal programs. The CRA works on a "one legal entity, one BN" policy: a single business is assigned one BN no matter how many locations or separate ventures it runs. The nine digits stay the same for the life of the business.
On its own, the nine-digit BN does nothing. It becomes useful only once you attach a program account to it. That is the piece most explanations skip, so it is worth walking through the structure.
How a business number is built: program accounts
A CRA program account covers one part of your dealings with the CRA. Each account extends the nine-digit BN with a two-letter program identifier and a four-digit reference number. Put together they form your full program account number:
123456789 RT 0001
└───────┘ └┘ └──┘
BN program reference
The reference number lets you hold more than one account of the same type. Your first GST/HST account is RT 0001; a second one, if you ever needed it, would be RT 0002. Here are the program accounts the CRA offers and who registers for each, drawn from its program accounts you may need page.
| Program account | Identifier | You register when |
|---|---|---|
| GST/HST | RT | You have to charge and collect GST/HST (you cross the $30,000 small-supplier threshold, or you drive a taxi or ride-share) |
| Payroll deductions | RP | You pay employees and withhold CPP, EI, and income tax |
| Corporation income tax | RC | Your business is incorporated |
| Information returns | RZ | You file returns such as the T5, T5013, or the T5018 for construction subcontractor payments |
| Import-export | RM | You import or export commercial goods (set up through the Canada Border Services Agency's CARM portal since October 21, 2024) |
One BN can carry several of these at once. A sole proprietor who registers for GST/HST and later hires staff ends up with 123456789 RT 0001 and 123456789 RP 0001 on the same business number.
Do you need a business number as a sole proprietor?
Here is where a lot of new owners register for something they do not need. According to the CRA, if your business is unincorporated you only need a BN when you register for a program account. No program account, no BN required.
A sole proprietor reports business income and expenses on the T1 income tax and benefit return, on lines 13500 to 14300, using Form T2125. That return runs on your social insurance number, not a BN. So a freelancer with no employees, earning under the $30,000 GST/HST threshold, and not importing goods can run a legitimate business for years without ever holding a business number.
You cross into needing one the moment a program account applies:
- Your worldwide taxable revenue passes $30,000 over four consecutive calendar quarters (or in a single quarter), which triggers GST/HST registration and an RT account.
- You hire your first employee, which requires a payroll RP account before the first remittance is due.
- You incorporate, which brings an RC account (more on that below).
- You start importing or exporting commercial goods and need an RM account.
Until one of those is true, the honest answer to "do I need a business number" is usually no.
Business number vs corporation number vs your SIN
These three identifiers get mixed up constantly, partly because incorporating gives you two of them at once. They are issued by different bodies and do different jobs.
| Identifier | Issued by | Format | What it is for |
|---|---|---|---|
| Business number (BN) | Canada Revenue Agency | 9 digits, plus a 2-letter and 4-digit suffix per program account | Your business's account with the CRA and linked government programs |
| Corporation number | Corporations Canada (part of ISED) | 7 digits, assigned at federal incorporation | Proof that your corporation exists as a legal entity |
| Social insurance number (SIN) | Service Canada | 9 digits | Your personal tax account; a sole proprietor files business income on the T1 under it |
The corporation number and the BN arrive together when you incorporate federally. Corporations Canada issues the corporation number when it approves your articles of incorporation, and, as the CRA notes on its corporation income tax program account page, you then receive a BN and an RC program account. The two numbers are not interchangeable: the corporation number identifies the legal entity to the corporate registry, while the BN identifies it to the tax system.
How to get a business number
When a program account applies, you set up the BN and the account together. Since November 3, 2025, the CRA requires new BN and program-account registrations to be done online through Business Registration Online (BRO). BRO creates the BN and adds a GST/HST, payroll, or other account in the same session, and you receive the number and a confirmation instantly. Save or print that confirmation, because the CRA does not send it separately.
To use BRO you need a CRA account. The CRA has moved away from phone registration: if you call the business enquiries line to register, it now directs you to BRO. Non-residents doing business in Canada can still register on Form RC1, Request for a Business Number and Certain Program Accounts, or use the CRA's non-resident online form.
Federal incorporation is a separate case: incorporating through Corporations Canada generates the BN and RC account for you, so you do not start a fresh BRO session for the number itself.
How to find or confirm an existing business number
A large share of BN searches come from owners who already have a number and cannot find it. The CRA lists the ways to find an existing business number:
- Your own records. The confirmation you saved or printed at the end of a BRO session shows the BN. So does any CRA correspondence about your accounts.
- Your CRA account. If you have added My Business Account, the BN appears on the welcome page when you sign in.
- Your provincial or territorial account. If you registered through your province or territory, the number is in that online portal.
The CRA also flags a quirk worth knowing: a BN may have been created for your business even if you did not finish registering, for example if a BRO session timed out. If you think you started a registration and are unsure whether a number exists, check before you register again, because a second attempt does not create a second BN for the same legal entity.
Common business number misconceptions
"I need a business number to start a sole proprietorship." You do not. The business exists as soon as you start operating under your own name or a registered trade name, and you file its income on your T1. The BN only enters the picture when a program account applies.
"My GST/HST number and my business number are different numbers." They share the same nine digits. Your GST/HST number is your BN with the RT program account and a reference number attached, such as 123456789 RT 0001. Registering for GST/HST does not give you a new base number.
"Incorporating replaces my business number with a corporation number." These are two separate identifiers issued by two separate bodies. The corporation number comes from Corporations Canada and proves the entity exists; the BN comes from the CRA and runs your tax accounts. You hold both.
Where SparkReceipt fits
A business number sits at the top of your tax paperwork, and the CRA expects the records underneath it to hold up. Once you have an RT account, every input tax credit you claim needs a supporting receipt showing the supplier's own GST/HST number, and every expense on your T2125 needs documentation. SparkReceipt captures each receipt the moment you get it, reads the vendor, amount, date, and tax, and files it in categories that line up with your return, so the paperwork behind each program account is ready before you file. You can see the whole year in one place with the expense tracker and pull a tax-ready summary with expense reports. Get Started for free.
Frequently asked questions
Is a business number the same as a GST/HST number?
The GST/HST number is your BN with an RT program account attached. The nine-digit root is identical; the GST/HST version adds the two-letter code and a reference number.
Does a sole proprietor need a business number? Only when a program account applies. A sole proprietor with no employees, under the $30,000 GST/HST threshold, and not importing goods does not need one and files on the T1 using their SIN.
Is a business number free? Yes. The CRA issues the BN and program accounts at no charge through Business Registration Online. You do not need to pay a third-party service to get one.
Can one business have more than one business number? No. The CRA assigns one BN per legal entity under its "one legal entity, one BN" policy, regardless of how many locations or separate ventures it runs. It can, however, carry several program accounts.
What is the difference between a business number and a corporation number? The corporation number is issued by Corporations Canada and proves your corporation exists as a legal entity. The business number is issued by the CRA and identifies the business to the tax system. When you incorporate federally you receive both.
How do I find my business number if I lost it? Check the confirmation from your registration session, sign in to My Business Account where it shows on the welcome page, or look in your provincial or territorial online account if you registered there.
Key takeaways
- A business number is the CRA's unique nine-digit identifier for your business, and you do not apply for it on its own.
- Program accounts attach to the BN with a two-letter code and a four-digit reference, such as
123456789 RT 0001for GST/HST. - The five program accounts are RT (GST/HST), RP (payroll), RC (corporation income tax), RZ (information returns), and RM (import-export).
- An unincorporated business gets a BN only when it registers its first program account; a sole proprietor otherwise files on the T1 under their SIN.
- The BN, the corporation number, and your SIN are three separate identifiers from three separate bodies; incorporating federally gives you the first two at once.
- The BN is free from the CRA, there is one per legal entity, and you can recover a lost one through your records, My Business Account, or your provincial portal.