What Is a T4 Slip?
A T4 slip (Statement of Remuneration Paid) is a tax form that Canadian employers must issue to every employee by the last day of February each year. It reports the total employment income paid and all deductions made during the previous calendar year. The CRA uses T4 information to verify your income tax return and calculate your refund or balance owing.
If you are employed in Canada and earn wages, salary, commissions, bonuses, or taxable benefits, you will receive a T4 slip. Understanding what each box means helps you file an accurate tax return and avoid costly CRA review letters.
Need help understanding your T4 or filing your taxes correctly? Contact Pathak Professional Corporation — your trusted CPA firm in Mississauga at 437-872-7399 or visit us at 48 Village Centre Place, Mississauga, ON L4Z 1V9.
T4 Slip: Complete Box-by-Box Breakdown
Here is every key box on the T4 slip and what it means:
| Box Number | Description | Where It Goes on Your Return |
|---|---|---|
| Box 14 | Employment income — your total gross salary, wages, and taxable benefits before deductions | Line 10100 of your T1 |
| Box 16 | Employee CPP contributions | Line 30800 (CPP credit) and Schedule 8 |
| Box 17 | Employee QPP contributions (Quebec only) | Line 30800 |
| Box 18 | Employee EI premiums paid | Line 31200 (EI premium credit) |
| Box 20 | RPP (Registered Pension Plan) contributions — reduces RRSP room | Line 20700 (pension adjustment) |
| Box 22 | Income tax deducted at source | Line 43700 (taxes deducted) — reduces balance owing |
| Box 24 | EI insurable earnings (used to calculate EI benefit entitlement) | Information only |
| Box 26 | CPP/QPP pensionable earnings | Information only |
| Box 29 | Employment code — type of employment (regular, seasonal, etc.) | Information only |
| Box 37 | Employer-paid dental insurance premiums (taxable benefit) | Included in Box 14 |
| Box 40 | Other taxable allowances and benefits (company car, gym, etc.) | Included in Box 14 |
| Box 44 | Union dues deducted | Line 21200 (union dues deduction) |
| Box 46 | Charitable donations deducted at source | Line 34900 (charitable donation credit) |
| Box 50 | RPP or DPSP registration number | Information only |
| Box 52 | Pension adjustment — reduces your next year’s RRSP contribution room | Line 20600 on T1 |
| Box 54 | Business number of your employer | Information only |
| Box 55 | Employee’s PPIP (Quebec) premiums | Quebec filers only |
| Box 57–60 | Employment income by period (COVID-era boxes, may still appear) | Historical — verify if still relevant |
How to Read Your T4: A Practical Example
Let’s say you earned $75,000 in 2024 as an employee in Ontario. Your T4 might show:
- Box 14 (Employment income): $75,000
- Box 16 (CPP contributions): $3,867.50 (the 2024 employee maximum)
- Box 18 (EI premiums): $1,049.12 (the 2024 employee maximum)
- Box 22 (Income tax deducted): Approximately $15,000–$18,000 depending on your withholding
- Box 52 (Pension adjustment): $3,000 if you have an RPP — this reduces your 2025 RRSP room
When you file your T1 return, Box 22 (income tax deducted) is credited against your total tax owing. If your employer deducted too much tax, you receive a refund. If too little was deducted (common with multiple jobs or bonuses), you owe the difference plus possible interest if not remitted quarterly.
T4 vs. Other Common Canadian Tax Slips
| Slip | What It Reports | Who Receives It |
|---|---|---|
| T4 | Employment income and deductions | Employees |
| T4A | Pension, retirement, annuity, other income (including CERB, contractor payments) | Pensioners, self-employed, grant recipients |
| T4A(OAS) | Old Age Security payments | OAS recipients 65+ |
| T4A(P) | Canada Pension Plan benefits | CPP benefit recipients |
| T4E | Employment Insurance benefits | EI recipients |
| T3 | Trust income (mutual fund distributions, estate income) | Investors in trusts/mutual funds |
| T5 | Investment income (dividends, interest) | Investors with non-registered accounts |
| T5008 | Securities transactions (capital gains reporting) | Investors who sold securities |
| T2200 | Employment expenses declaration (for claiming home office, vehicle, etc.) | Employees claiming work expenses |
What to Do If Your T4 Is Wrong or Missing
T4 Is Wrong (Incorrect Box Amounts)
If you believe your T4 contains errors:
- Contact your employer’s payroll department immediately and request a corrected T4 (called an amended T4 or T4 Amendment)
- Do not file your taxes until you receive the corrected slip — filing with incorrect information creates a discrepancy the CRA may flag
- If your employer refuses or cannot be reached, the CRA can often supply your income information from what your employer reported directly to them. Call CRA at 1-800-959-8281
T4 Not Received by March 1
Employers are legally required to issue T4s by the last day of February. If you haven’t received yours:
- Check your employer’s HR portal — many T4s are issued digitally
- Contact your employer’s payroll department directly
- Log in to My Account on the CRA website — your T4 information from your employer is usually available by mid-March
- If you must file before receiving your T4, use your last pay stub to estimate employment income and request an extension or file an amended return later
Multiple T4 Slips: What to Do
If you worked multiple jobs in the same year, you will receive multiple T4 slips — one from each employer. Here’s what you need to know:
- CPP over-contribution: Each employer deducts CPP independently. If you earned over the pensionable maximum from multiple employers combined, you will have over-contributed. The CRA will refund the excess CPP when you file your return — it appears on Line 44800 of your T1
- EI over-contribution: Same issue — multiple employers deduct EI premiums separately. Excess EI is also refunded via your return
- Report ALL T4s: The CRA cross-references all T4s filed by employers. Missing one is a common audit trigger
- Add up all Box 14 amounts: Your total income for the year is the sum of all Box 14 amounts across all your T4 slips
T4 and RRSP Contribution Room
Your T4 directly affects how much you can contribute to your RRSP:
- RRSP room formula: 18% of your prior year’s earned income (Box 14 of your T4) minus any pension adjustment (Box 52)
- Example: If your 2024 Box 14 = $75,000 and Box 52 = $3,000: RRSP room = ($75,000 × 18%) − $3,000 = $13,500 − $3,000 = $10,500 in new 2025 RRSP room
- The CRA confirms your actual RRSP limit on your Notice of Assessment (NOA) after each year’s filing
Filing Your Return Using Your T4: Step-by-Step
- Gather all T4 slips — check your employer portal, email, and CRA My Account
- Enter Box 14 on Line 10100 of your T1 General return
- Enter Box 22 (income tax deducted) on Line 43700 — this is your most important number for calculating your refund
- Claim CPP credit: Box 16 → Line 30800 for the non-refundable tax credit
- Claim EI premium credit: Box 18 → Line 31200
- Report taxable benefits: They’re already in Box 14, so no separate entry needed
- Claim union dues: Box 44 → Line 21200
- Confirm RRSP room: Use your NOA or CRA My Account to verify before contributing
Common T4 Mistakes That Trigger CRA Reviews
- Not reporting all T4 slips (especially from short-term or seasonal jobs)
- Misreading Box 14 and confusing gross employment income with net pay on your paycheque
- Forgetting to include taxable benefits shown in Box 40 (already in Box 14 but must reconcile)
- Failing to report T4 slips from U.S. employers if you worked cross-border
- Missing the pension adjustment in Box 52 and over-contributing to your RRSP
If you received a CRA review or discrepancy letter related to your T4 information, our Mississauga CPA team can represent you and resolve the issue. Contact Pathak Professional Corporation at 437-872-7399.
Frequently Asked Questions About T4 Slips
When do employers have to send T4 slips in Canada?
Employers must issue T4 slips to employees and file them with the CRA by the last day of February of the following calendar year. For the 2024 tax year, the deadline is February 28, 2025. Failure to issue T4s by this deadline can result in CRA penalties for the employer.
Can I file my taxes without my T4?
Yes — if your T4 is late, you can estimate your income using your last December pay stub. File your return and note that you are waiting for your T4. Once received, file an amended T1 if any numbers differ. Alternatively, check CRA My Account where employer-reported T4 data is usually available by mid-March, even if your physical slip hasn’t arrived.
What is the difference between Box 14 and my net pay?
Box 14 is your gross employment income — the total amount earned before any deductions. Your net pay (what actually hits your bank account) is lower because CPP premiums (Box 16), EI premiums (Box 18), income tax (Box 22), and any other deductions have been subtracted. Always use Box 14 (gross income), not your net pay, when reporting employment income on your tax return.
Does Box 52 (pension adjustment) reduce my taxes?
No — Box 52 does not directly reduce the taxes you pay. It reduces your RRSP contribution room for the following year. This is because your employer-sponsored RPP or DPSP is already building retirement savings on your behalf, so the CRA reduces your RRSP room to prevent double tax-sheltering. A higher pension adjustment reduces future RRSP flexibility, but it also means your employer-sponsored plan is well-funded.
