A T4 tax form, formally the T4 Statement of Remuneration Paid, is the year-end slip your Canadian employer issues to report what they paid you and what they withheld for the calendar year. Every employee who earned wages, salary, commissions, bonuses, vacation pay, or taxable benefits receives one. It’s the starting point for your personal income tax return because it sets out your gross employment income and the amounts already sent to the government on your behalf for income tax, Canada Pension Plan contributions, and Employment Insurance premiums.
Reading the Numbered Boxes
Each numbered box maps to a specific line on your tax return. Four do most of the work:
- Box 14 reports your employment income: total earnings before deductions, including salary, commissions, and the value of taxable benefits. This is the headline figure that flows onto your return.
- Box 16 shows the employee share of Canada Pension Plan contributions your employer withheld.
- Box 18 shows the employee share of Employment Insurance premiums deducted from your pay.
- Box 22 shows the income tax withheld. For most of Canada, this combines federal and provincial or territorial tax. In Quebec, Box 22 covers federal tax only; provincial tax appears on a separate slip.
Box 14 often looks larger than the cash you actually received. That’s because it includes non-cash taxable benefits such as employer-provided parking, group term life insurance premiums, subsidized housing, gifts and awards above $500 in fair market value, and stock option benefits.
CPP, CPP2, and EI
CPP contributions are split evenly between you and your employer, and Box 16 reports the first-tier employee amount. Since 2024, a second tier called CPP2 applies to earnings above the first ceiling and up to a higher ceiling; when it applies, it appears separately in the “Other information” area rather than in Box 16. The CRA reconciles these amounts against your actual pensionable earnings when you file, which matters if you held multiple jobs and your combined earnings crossed a ceiling.
EI premiums fund temporary income support during job loss, parental leave, and certain other interruptions. Your employer withholds them from each paycheque and reports the total in Box 18. If you worked for more than one employer and overpaid across your combined slips, you get the excess back as a credit when you file.
Other Information Codes That Affect Your Return
Below the main boxes, employers report additional items using numbered codes. Two come up regularly:
- Code 44 reports union or professional dues deducted from your pay, including any GST/HST. You claim the amount as a deduction on line 21200. Initiation fees, special assessments, and pension-plan charges don’t qualify even when they appear on the same receipt.
- Code 85 reports employee-paid premiums for a private health services plan. Reporting it is optional for employers, but when it appears, you can claim those premiums as a medical expense. The amount in Code 85 is not included in Box 14.
Other codes flag specific taxable benefits, stock option deductions, and employment commissions. If you see one you don’t recognize, the CRA’s T4 guide lists every code with a plain explanation.
When Your T4 Should Arrive
Employers must issue T4 slips by the last day of February following the calendar year. For the 2025 tax year, your slip should arrive by the end of February 2026, whether by mail or through a secure employer portal.
If early March arrives and you still don’t have it, contact your employer’s payroll department first. If you can’t reach them or the company has shut down, log in to CRA My Account. The CRA posts copies of T4 slips once employers file them, so yours may already be there even if the paper copy hasn’t shown up.
Filing Your Return With Your T4
Your T4 feeds directly into the T1 General Income Tax and Benefit Return. Most people use CRA-certified tax software, which can pull slip data automatically through Auto-fill my return. The service connects to the CRA’s database and populates the relevant fields, so you’re not manually copying numbers and risking transcription errors.
Once the return is complete, you submit it electronically through NETFILE using the same certified software. Electronic filing is faster and typically produces refunds weeks sooner than paper. If you prefer paper, you can print and mail the return to a CRA tax centre with copies of your T4 slips attached.
Either way, the numbers on your return need to match what the CRA already has on file from your employer’s submission. A mismatch between your reported income and your T4 is one of the most common triggers for a reassessment notice.
Filing Deadlines
For the 2025 tax year, the deadline to file and pay any balance owing is April 30, 2026. If you or your spouse or common-law partner are self-employed, the filing deadline extends to June 15, 2026, but taxes owed are still due by April 30.
Missing the payment deadline means interest on the unpaid balance. For the first half of 2026, the CRA’s prescribed rate on overdue income tax is 7% per year, compounded daily, starting May 1. A late-filing penalty applies on top of that, so filing on time even when you can’t pay the full amount is almost always the better move.
If Your T4 Is Wrong
When an employer discovers an error after issuing a slip, they file a corrected version. An amended T4 carries Type Code “A,” which tells the CRA the new figures replace the originals. Common triggers include miscalculated taxable benefits, incorrect pensionable or insurable earnings, or a wrong Social Insurance Number. If a slip was issued to the wrong person or shouldn’t have been issued at all, the employer files a cancelled slip with Type Code “C.” Your My Account records should reflect the change within a few weeks of the correction being submitted.
If you spot an error, don’t adjust the numbers on your return and hope for the best. Contact your employer and ask for an amended slip. Filing a return that doesn’t match the CRA’s records invites a reassessment, and sorting it out afterward takes longer than fixing the slip upfront.
Quebec Employees Also Get an RL-1
If you worked in Quebec during the year, you’ll receive both a T4 and a Relevé 1 (RL-1). The T4 handles federal reporting; the RL-1 covers Quebec provincial tax, Quebec Pension Plan contributions, and Quebec Parental Insurance Plan premiums. Box 22 on a Quebec employee’s T4 reflects only the federal tax withheld, and provincial tax appears in Box E of the RL-1. You need both slips to complete your federal and provincial returns.
How Long to Keep Your T4
The CRA requires you to keep tax records, including T4 slips, for at least six years from the end of the tax year they relate to. A T4 for the 2025 tax year should be kept until at least the end of 2031. This applies even if you filed electronically and the CRA already has a digital copy. If you’re audited or need to support a deduction, the burden is on you to produce the documentation.
US Citizens Working in Canada
If you’re a US citizen or green card holder earning employment income in Canada, your T4 matters for two tax systems. The United States taxes its citizens on worldwide income regardless of where they live, so Canadian wages reported on a T4 must also be reported on your US federal return.
Two mechanisms prevent most people from being taxed twice. The Foreign Earned Income Exclusion, claimed on Form 2555, lets you exclude up to $132,900 of foreign earned income for 2026 if you meet either the bona fide residence test or the physical presence test. The Foreign Tax Credit, claimed on Form 1116, generally allows the Canadian income tax withheld (Box 22 plus any provincial tax) to be claimed against your US liability. You’ll convert the Canadian dollar amounts to US dollars using the exchange rate on the date the tax was withheld.
The US-Canada tax treaty adds another layer. Under Article XV, a US resident’s Canadian employment income may be exempt from Canadian tax entirely if the remuneration was under $10,000 CAD for the year, or if the worker was present in Canada for fewer than 183 days and was paid by a non-Canadian employer with no permanent establishment in Canada. Most people working full-time in Canada won’t meet those conditions, but short-term assignments sometimes qualify. Coordinating filings across both countries is genuinely complicated, and cross-border professional fees typically run several hundred dollars above a straightforward domestic return.