What Is a Canada Tax ID Number? Types and How to Register

A Canada tax ID number is a government-issued identifier used to track your obligations and entitlements in the Canadian tax system, and the country uses four different ones depending on your situation. Individuals need a Social Insurance Number (SIN). Businesses need a Business Number (BN). Non-residents who owe Canadian tax but can’t get a SIN need an Individual Tax Number (ITN). Estates and trusts filing T3 returns need a Trust Account Number. Each has its own issuer, application form, and timeline, and picking the wrong one — or getting the right one too late — can block a filing or trigger a penalty.

The Four Canadian Tax ID Numbers

The Social Insurance Number is a nine-digit number for Canadian citizens, permanent residents, and authorized temporary residents. You need it to work in Canada, file a personal income tax return, and access programs like the Canada Pension Plan and Employment Insurance. Service Canada issues it, not the CRA.¹

The Business Number is a nine-digit CRA identifier that anchors all your business’s program accounts. GST/HST collection, payroll, corporate income tax, and import/export activity each get their own sub-account attached to the same BN, with a two-letter identifier and a four-digit reference (for example, 123456789 RT0001 for GST/HST).²

The Individual Tax Number is a nine-digit number for non-residents who aren’t eligible for a SIN but have Canadian tax obligations. Common triggers include selling Canadian property, earning Canadian rental income, or being an international student who needs to file a return without work authorization.³

The Trust Account Number starts with the letter “T” followed by eight digits, and estates and trusts need it to file T3 returns electronically.⁴

Getting a Social Insurance Number

You’re eligible for a SIN if you’re a Canadian citizen, a permanent resident, or a temporary resident authorized to work or study. There’s no fee. The documents you provide must be current originals — photocopies aren’t accepted.⁵

Canadian citizens: A provincial or territorial birth certificate, or a Certificate of Canadian Citizenship issued by Immigration, Refugees and Citizenship Canada (IRCC).
Permanent residents: A PR Card, or a Confirmation of Permanent Residence (accepted only within one year of becoming a permanent resident).
Temporary residents: A valid work permit, a study permit that explicitly states you “may accept employment” or “may work” in Canada, a visitor record authorizing work, or a diplomatic identity card with work authorization.

How to Apply

You can apply online, in person at a Service Canada Centre, or by mail. Online is fastest; if everything is in order, the application is processed within five business days, and you can view and print your SIN through My Service Canada Account without waiting for anything by mail. If you apply in person, you receive your SIN during the visit.⁶

Temporary SINs Beginning With “9”

If you’re a temporary resident, your SIN begins with “9” and carries an expiry date that matches your immigration document. When you renew your work or study permit, the SIN doesn’t update automatically. Once your new physical permit arrives from IRCC, submit a new SIN application so Service Canada can update the expiry on your record. An IRCC approval email isn’t enough — you need the physical document in hand.⁶

Getting a Business Number

Any business that interacts with the CRA needs a Business Number — whether that’s collecting GST/HST, running payroll, filing a corporate return, or importing goods. Before you register, gather your business’s legal name, operating name, physical address, a description of your activity, and your fiscal year-end date.

How to Register

The CRA’s Business Registration Online (BRO) portal is the primary channel. It lets you create your BN and register for all needed program accounts in a single session with instant confirmation. As of November 2025, the CRA no longer accepts BN or program account registrations by phone.⁷

If you can’t register online, you can complete Form RC1 (Request for a Business Number and Certain Program Accounts) and mail it to your CRA tax centre. The form covers GST/HST, payroll deductions, corporate income tax, registered charities, and information returns. Some newer accounts, including the Underused Housing Tax and Luxury Tax, cannot be registered by mail.⁷

The Program Accounts You’ll Likely Need

Payroll deductions (RP): Required as soon as you hire your first employee and start remitting income tax, CPP, and EI deductions.
GST/HST (RT): Required once your worldwide taxable supplies exceed $30,000 over four consecutive calendar quarters, or $30,000 in a single quarter. You have 29 days from your effective registration date to complete registration.⁸
Corporation income tax (RC): Required for all incorporated businesses. Every resident corporation must file a T2 return each tax year, even if no tax is owed.⁹
Import/export (RM): Required if the business imports or exports goods.

When Your Business Structure Changes

Incorporating a sole proprietorship does not carry your existing BN over. The new corporation gets a brand-new BN and a new RC account, and any GST/HST or payroll accounts tied to the old BN won’t transfer — you’ll register those again under the new BN and close the old ones.¹⁰ Similarly, if a sole proprietorship is sold, the new owner cannot use the previous owner’s BN and must register a new one with fresh program accounts.¹¹

Getting an Individual Tax Number as a Non-Resident

If you’re a non-resident with Canadian tax obligations and you aren’t eligible for a SIN, you need an ITN. It lets you file Canadian returns, apply for reduced withholding tax, or request a clearance certificate when selling taxable Canadian property under Section 116 of the Income Tax Act.³

Non-residents earning Canadian rental income have a particular reason to get one: electing to file under Section 216 of the Income Tax Act. This election lets you pay tax on your net rental income at graduated rates instead of the flat 25% withholding on gross rent.¹²

How to Apply

Complete Form T1261 (Application for a CRA Individual Tax Number for Non-Residents). Check the box indicating why you need the ITN — skipping it causes processing delays. Include original identity documents or certified copies (passport, driver’s licence, or birth certificate). Certified copies must be signed in original ink by a public notary, lawyer, medical physician, or chartered professional accountant, and the certifier must include their title, address, contact number, and (for accountants) membership identification number.

Mail or courier the form and documents to:

Attn: ITN Unit
Services and Benefits, Section Benefits Division
Sudbury Tax Centre
1050 Notre Dame Ave
Sudbury, ON P3A 5C1
Canada

Allow six to eight weeks after the CRA receives your application before your ITN arrives in writing. If you’re selling Canadian property, submit your ITN application well in advance and separately from your disposition request; the CRA processes them through different channels, and bundling them causes delays.¹³

Getting a Trust Account Number

A trust must have a Trust Account Number before it can file a T3 return electronically. You can apply online through the Trust Account Registration feature in My Account, My Business Account, or Represent a Client. If you can’t register online, you can submit Form T3APP by mail.¹⁴

One exception: a Graduated Rate Estate, the estate of a recently deceased individual during the 36-month period after death, uses the deceased person’s SIN on the T3 return rather than a separate trust account number.⁴

Penalties for Not Registering on Time

Failing to provide a SIN when requested by an employer or another party that files information returns carries a $100 penalty per failure. The penalty doesn’t apply if you’ve already applied and just haven’t received your number yet, but you must apply within 15 days of the request and provide the number within 15 days of receiving it.¹⁵

For businesses, late GST/HST registration is where the pain lands. Once you cross the $30,000 small supplier threshold, you have 29 days to register. Miss that window and you’re on the hook for GST/HST that should have been collected during the period you were unregistered — money you probably didn’t charge your customers and now owe out of pocket.⁸

Keeping Your Tax ID Safe

Your SIN is the key to your identity in the Canadian tax system. Don’t carry it in your wallet and don’t share it unless legally required. Employers, banks, and government agencies are the main legitimate requesters. If your SIN card or confirmation letter is lost or damaged but you still know your number, no action is required — you can view and print your SIN by signing into My Service Canada Account.¹

If you’ve forgotten your SIN entirely, you can request confirmation by submitting a new application with all required documents. That doesn’t give you a new number; it confirms your existing one. A brand-new SIN is only issued when there’s clear evidence your current number has been used fraudulently.

For businesses, keep the CRA updated when ownership or structure changes. If a partner joins or leaves a partnership, the partnership may be considered a new legal entity requiring a new BN altogether.¹¹ Corporate structure changes must first be updated with your incorporating authority before the CRA will process them.

1
Government of Canada. Social Insurance Number – Overview
2
Canada Revenue Agency. Business Number and CRA Program Accounts
3
Canada Revenue Agency. Applying for an Individual Tax Number (ITN)
4
Canada.ca. T3 Trust Guide
5
Government of Canada. Required Documents – Social Insurance Number
6
Government of Canada. Social Insurance Number – Apply, Update or Obtain a SIN Confirmation
7
Canada Revenue Agency. Register as a Resident With a Canadian Business
8
Canada.ca. Find Out if You Have to Register for a GST/HST Account
9
Canada Revenue Agency. Corporation Income Tax Return
10
Government of Canada. Change of Legal Status
11
Government of Canada. Change of Owners, Partners or Directors
12
Canada Revenue Agency. Electing Under Section 216
13
Canada Revenue Agency. Disposing of or Acquiring Certain Canadian Property
14
Government of Canada. Application for a Trust Account Number
15
Justice Canada. Income Tax Act – Section 162