What Is a Canadian Tax ID Number? The Four Types and How to Apply

A Canada tax ID number is one of several nine-digit identifiers the federal government uses to track tax obligations, and which one you need depends on your situation. Individuals working or filing personal taxes need a Social Insurance Number (SIN). Businesses dealing with the Canada Revenue Agency need a Business Number (BN). Non-residents with Canadian tax obligations who can’t get a SIN need an Individual Tax Number (ITN). Estates and trusts filing a T3 return need a Trust Account Number. Each has its own issuer, application route, and timeline.

The Four Numbers and Who Needs Which

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

The Business Number is a nine-digit identifier the CRA assigns to businesses and other entities. It anchors all your CRA program accounts. GST/HST collection, payroll deductions, corporate income tax, and import/export activity each get their own sub-account attached to the same BN.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 otherwise needing to file a Canadian return.³

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

How to Get 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.¹

The documents you provide depend on your status, and they must be current originals. Photocopies aren’t accepted.⁵

Canadian citizens: a birth certificate from your province or territory of birth, or a Certificate of Canadian Citizenship issued by IRCC.
Permanent residents: a Permanent Resident Card, or a Confirmation of Permanent Residence within one year of becoming a permanent resident.
Temporary residents: a valid work permit, or a study permit stating you “may accept employment” or “may work” in Canada. A visitor record authorizing work or a diplomatic identity card with work authorization also qualifies.

You can apply online, in person at a Service Canada Centre, or by mail. Online applications process within five business days if everything is in order, and you can view and print your SIN through My Service Canada Account without waiting for a letter.⁶ In-person applicants get their SIN during the visit.⁷

Temporary SINs Beginning With 9

If you’re a temporary resident, your SIN begins with the digit “9” and carries an expiry date that matches your immigration document.¹ When you renew your work or study permit, the SIN doesn’t update automatically. Once you have the new physical permit, submit a new SIN application so Service Canada can update the expiry date. The dates on your SIN record and your immigration document must match.⁷

How to Register for a Business Number

Any business that interacts with the CRA needs a Business Number. That includes collecting GST/HST, running payroll, filing corporate tax returns, or importing goods. The BN itself is nine digits, and each program account adds a two-letter identifier and a four-digit reference. A GST/HST account looks like 123456789 RT0001.²

Before you register, gather your business’s legal name, operating name, physical address, a description of your business activity, and your fiscal year-end date.

The CRA’s Business Registration Online (BRO) portal is the primary channel. It lets you create the BN and register for all needed program accounts in one session, with instant confirmation. As of November 2025, the CRA no longer accepts BN or program account registrations by phone.⁸

If you can’t register online, you can complete Form RC1 and mail it to your CRA tax centre. RC1 covers GST/HST, payroll deductions, corporate income tax, registered charities, and information returns, but not newer accounts like the Underused Housing Tax and Luxury Tax.⁸

Common Program Accounts

Most businesses don’t need every account right away. The ones you’ll encounter most:

Payroll deductions (RP): required as soon as you hire your first employee and need to remit income tax, CPP, and EI on their behalf.
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 the registration.⁹
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.¹⁰
Import/export (RM): required if the business imports or exports goods.

When Your Business Structure Changes

If you incorporate a sole proprietorship, your existing BN does not carry over. The new corporation gets a brand-new BN and a new corporation income tax account. Any GST/HST or payroll accounts tied to the old BN won’t transfer automatically; you register those under the new BN and close the old ones.¹¹

The same applies when a sole proprietorship is sold. The new owner cannot use the previous owner’s BN and must register for a new one with fresh program accounts.¹²

How to Get an Individual Tax Number

Non-residents with Canadian tax obligations who aren’t eligible for a SIN apply for an ITN. It lets you file a Canadian return, apply for reduced withholding tax, or request a clearance certificate when selling taxable Canadian property under Section 116 of the Income Tax Act.³ International students without work authorization who still need to file a return also use the ITN.

Non-residents earning Canadian rental income have a second reason to get one: electing to file under Section 216. This election lets you pay tax on net rental income at graduated rates rather than the flat 25% withholding on gross rent.¹³

You apply by completing Form T1261. Check the box indicating why you need the ITN; skipping it delays processing. Fill in your identification details, and if your mailing address and foreign home address differ, provide both.³

You must include either original identity documents or certified copies. A passport, driver’s licence, or birth certificate is acceptable. Copies must be certified by a public notary, lawyer, medical physician, or chartered professional accountant, with an original ink signature, official title, address, and contact number. Accountants must also include their membership identification number.

Mail the completed form and documents to the ITN Unit at the Sudbury Tax Centre. Allow six to eight weeks after the CRA receives your application before you receive your ITN 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.¹⁴

Trust Account Numbers

An estate or trust that needs to file a T3 return requires a Trust Account Number, which starts with the letter “T” followed by eight digits. It’s separate from a SIN or BN, and a trust must have one before it can file electronically.⁴

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, submit Form T3APP by mail.¹⁵

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 Missing or Late Registration

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 for a SIN and haven’t received it yet, but you must apply within 15 days of the request and provide the number within 15 days of receiving it.¹⁶

For businesses, late GST/HST registration is the more expensive mistake. Once you cross the $30,000 small supplier threshold, you have 29 days to register. If you don’t, you’re responsible for GST/HST that should have been collected during the period you were unregistered, money you likely didn’t charge your customers and now owe out of pocket.⁹

Protecting and Updating Your Number

Your SIN is the key to your identity in the Canadian tax system. Don’t carry it in your wallet or share it unless legally required; employers, banks, and government agencies are the main legitimate requesters. If your SIN card or confirmation letter is lost but you still know your number, no action is needed. You can view and print your SIN by signing into My Service Canada Account.¹ If you’ve forgotten it entirely, you can request confirmation by submitting a new application with the required documents. That confirms your existing number rather than issuing a new one. A brand-new SIN is only issued when there’s clear evidence the 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.¹² 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 – Receiving and Updating Your SIN
7
Government of Canada. Social Insurance Number – Apply, Update or Obtain a SIN Confirmation
8
Canada Revenue Agency. Register as a Resident With a Canadian Business
9
Canada.ca. Find Out if You Have to Register for a GST/HST Account
10
Canada Revenue Agency. Corporation Income Tax Return
11
Government of Canada. Change of Legal Status
12
Government of Canada. Change of Owners, Partners or Directors
13
Canada Revenue Agency. Electing Under Section 216
14
Canada Revenue Agency. Disposing of or Acquiring Certain Canadian Property
15
Government of Canada. Application for a Trust Account Number
16
Justice Canada. Income Tax Act – Section 162