CRA business number: What it is and how to get one

Key takeaways

• A CRA business number is a 9-digit identifier the Canada Revenue Agency assigns to your business as a permanent federal tax ID
• You need one to charge GST/HST, run payroll, import or export commercial goods, or operate as an incorporated business
• The fastest way to get a CRA business number is through the Business Registration Online portal, which issues it instantly
• The 9-digit number stays constant, but the CRA adds a 2-letter program code and 4-digit reference to create separate 15-character IDs for GST/HST, payroll, corporate income tax, and information returns

A CRA business number is the 9-digit identifier the Canada Revenue Agency uses to track your business across every federal tax program. Once assigned, it stays with your business permanently and follows you across GST/HST filings, payroll remittances, corporate income tax returns, and import or export activity.

If you're starting a business in Canada, running payroll for the first time, or crossing the $30,000 GST/HST revenue threshold, your CRA business number is the first thing you need to set up.

What is a CRA business number?

The CRA business number (BN) is a unique 9-digit number that acts as your permanent federal tax ID. It covers all your interactions with the Canada Revenue Agency and most provincial and municipal programs.

The number itself is only nine digits. What makes it useful is the program account system the CRA layers on top of it. The CRA appends a 2-letter code and a 4-digit reference to your base BN, creating a 15-character identifier for each type of tax account you register for. Your GST/HST account, payroll account, and corporate income tax account all share the same 9-digit root but have different extensions.

This means you only deal with one identity at the CRA, even when you file multiple types of returns.

Who needs a CRA business number?

You need a CRA business number if you charge GST/HST, hire employees, import or export commercial goods, or operate as an incorporated business.

• Charging GST/HST: You must register for a GST/HST account once you exceed $30,000 in taxable revenue in a single calendar quarter, or in four consecutive calendar quarters. Both thresholds apply independently, so if one big quarter pushes you over $30,000 on its own, that triggers registration. Some businesses register voluntarily before hitting the threshold to claim input tax credits.
• Hiring employees: If you pay salaries, wages, or taxable benefits, you need a payroll deductions account to remit income tax, CPP contributions, and EI premiums to the CRA
• Importing or exporting commercial goods: A BN with an import-export program account is required to clear goods through the Canada Border Services Agency
• Operating as an incorporated business: Federal and provincial corporations need a BN for corporate income tax filings, even before they have employees or hit the GST/HST threshold

If you're a sole proprietor operating under your own legal name without employees, without imports, and below the $30,000 revenue threshold, you generally don't need a BN. You can file business income using your Social Insurance Number (SIN) on your personal tax return. If any of those conditions changes, BN registration becomes mandatory.

How do you register for a CRA business number?

The fastest way to register for a CRA business number is through the Business Registration Online (BRO) portal, which issues your BN within minutes. You can also mail or fax Form RC1, and in many cases a BN is issued automatically as part of provincial or federal incorporation.

1. Business Registration Online

The Business Registration Online portal lets you complete your application on the CRA website and receive your BN at the end of the session. You can also open program accounts for GST/HST, payroll, corporate income tax, and import-export at the same time, so you can finish your federal tax setup in one sitting.

You'll need basic information about your business:

• Legal name and operating name (if different)
• Business structure (sole proprietorship, partnership, or corporation)
• Business activity description
• Details about the program accounts you want to open

2. Form RC1 by mail or fax

If you can't or don't want to register online, you can complete Form RC1, Request for a Business Number and Certain Program Accounts, and send it to your local tax centre by mail or fax. Processing takes longer than the online route, usually a few weeks, so this option works best when you don't have an immediate filing deadline.

3. Through provincial incorporation

If you incorporate federally with Corporations Canada or provincially through your province's registry, a CRA business number is often generated as part of the incorporation process. In most provinces, the registry shares your incorporation details with the CRA directly, and your BN arrives without a separate application.

Check your incorporation paperwork before registering through the BRO portal. You might already have a BN you didn't realize was issued.

What is the 15-character CRA program account ID?

The 15-character program account ID is your 9-digit BN plus a 2-letter program code and a 4-digit reference number that identifies a specific tax account. Each program account you open at the CRA gets one.

The reference number distinguishes between multiple accounts of the same type. Most businesses have only one of each, so the reference defaults to 0001, while larger organizations with multiple divisions or branches might have RT0001, RT0002, RT0003 for different GST/HST accounts.

These are the four most common program codes.

When you correspond with the CRA, the program account ID tells them which specific tax stream you're asking about. When you file a GST/HST return, you reference your RT account, and when you remit payroll source deductions, you reference your RP account. Mixing them up is a common source of misapplied payments and reconciliation problems at year-end.

How do you find your existing CRA business number?

You can find your existing CRA business number through CRA My Business Account, past CRA correspondence, the CRA Business Enquiries line, or your accountant.

• CRA My Business Account: Log in to the My Business Account portal. Your BN and every program account associated with it appear on the main dashboard. This is the most reliable way to find your number and any active program accounts.
• Past CRA correspondence: Notices of Assessment, GST/HST returns, payroll remittance vouchers, and T4 summaries all include your BN and the relevant program account ID. If you have any prior CRA mail on file, the number is likely on it.
• CRA Business Enquiries line: Call 1-800-959-5525 for general account support. You'll need to verify your identity before the agent can confirm the number.
• Your accountant or bookkeeper: If you've worked with an external accountant, they almost certainly have your BN on file. Asking them is often faster than working through the CRA directly.

How do you use your CRA business number day to day?

Your business number is the reference point for nearly every interaction with the CRA. If you charge GST/HST, add your registration number to your invoices so your customers can claim their input tax credits. Use the appropriate program account ID when remitting payroll deductions, filing T4s, paying corporate income tax, or filing GST/HST returns.

The CRA also requires you to keep your business information current. If your legal name, address, or business structure changes (for example, a sole proprietorship that incorporates), you need to update the CRA. In some cases, like a change in legal structure, you'll need a new BN entirely because the old entity no longer exists from a tax perspective.

How do you get organized before you register?

A few hours of preparation before you register can save you from filing corrections later. Getting these details sorted ahead of time makes the process faster.

1. Confirm your legal business name and structure: Sole proprietorship, partnership, federal corporation, and provincial corporation each carry different filing obligations. Get this right before registering.
2. Decide which program accounts you need now: You can open a GST/HST account, payroll account, and others during the same BRO session, but only register for accounts you'll use in the next few months. Opening accounts you don't need creates filing obligations.
3. Gather your basic business details: Mailing address, business activity description, expected annual revenue, and the date you started or plan to start each activity
4. Decide on your GST/HST reporting period: Most small businesses file annually, but you can elect to file quarterly or monthly. Annual filing is simpler, and more frequent filing improves cash flow if you regularly claim input tax credits.
5. Set up a system to track filing deadlines: Once your accounts are active, missed filings create penalties even if you owe nothing. A simple calendar with reminders for each program account's deadlines is enough at the start.

How do you stay organized after registration?

Getting your CRA business number is the easy part. What comes next is where most early-stage businesses run into trouble: filing returns on time, remitting payroll deductions accurately, tracking GST/HST collected and paid, and keeping clean records for each program account.

The underlying problem is usually the same—transactions, receipts, and tax codes live in different places, and someone on the finance team has to pull it all together manually before every filing deadline. When you're hand-coding HST/GST/PST line by line in QuickBooks or Xero, chasing down employee receipts over email, and reconciling spend across separate bank cards, the month-end close becomes the bottleneck.

The fix is getting your systems to do that work as transactions happen, not after. That means expenses are categorized and tax-coded the moment they're incurred, receipts are captured and matched automatically, and bill payments flow through a system that gives you a clean audit trail your ERP can actually use.

Ramp brings that together for Canadian businesses. Corporate cards in CAD and USD on a single login, automated expense management with HST/GST/PST/QST auto-coding, bill pay with native sync to QuickBooks Online, Xero, NetSuite, Sage Intacct, and Microsoft Dynamics Business Central—all in one platform. No more reconciling across three or four tools. No more manual tax coding at month-end.

Canadian businesses that switch to Ramp save an average of 5% and close their books faster1. See what it looks like for your team.

Explore Ramp for Canadian businesses →