T4 Slip Explained: Understanding Your Employment Income

Key T4 Boxes Explained

Your T4 contains many boxes, but these are the most important ones for your tax return:

Box 14 - Employment Income

This is your total employment income before deductions. It includes:

Salary and wages
Commissions
Bonuses
Taxable benefits (like employer-paid life insurance)
Vacation pay

CRA Line: Report on Line 10100 of your tax return.

Box 16 - Employee's CPP Contributions

The amount you contributed to the Canada Pension Plan. For 2024, the employee rate is 5.95% on earnings between $3,500 and $68,500.

Maximum for 2024: $3,867.50

CRA Line: Report on Line 30800 (base) and Line 30900 (enhanced).

Box 17 - Employee's QPP Contributions

For Quebec employees only - contributions to the Quebec Pension Plan instead of CPP.

Box 18 - Employee's EI Premiums

Your Employment Insurance premiums. For 2024, the rate is 1.66% on insurable earnings up to $63,200.

Maximum for 2024: $1,049.12

CRA Line: Report on Line 31200.

Box 22 - Income Tax Deducted

The total federal and provincial income tax your employer withheld from your pay throughout the year.

CRA Line: Report on Line 43700.

Box 24 - EI Insurable Earnings

The portion of your income that was subject to EI premiums. May differ from Box 14 if you have non-insurable income.

Box 26 - CPP/QPP Pensionable Earnings

Income subject to CPP/QPP contributions. Used to calculate your CPP credits.

Taxable Benefits on Your T4

Certain employer-provided benefits are taxable and included in Box 14:

Box 40 - Other Taxable Allowances and Benefits

Company car for personal use
Employer-paid group term life insurance (over $25,000)
Non-accountable expense allowances
Employer-paid parking (in some cases)

Box 57 - Employment Income (March 15 to May 9, 2020)

COVID-related box - shows income earned during the initial lockdown period.

RRSP-Related Boxes

Box 52 - Pension Adjustment

If you have a workplace pension or DPSP, this amount reduces your RRSP contribution room for the following year. It represents the value of pension benefits you accrued.

Box 50 - RPP Contributions

Your contributions to a Registered Pension Plan. Deductible on Line 20700.

Union and Professional Dues

Box 44 - Union Dues

Amounts you paid in union or professional dues, which are deductible on Line 21200.

What to Do If Your T4 Is Wrong

Contact your employer first - They may issue a corrected T4 (T4 Amendment)
Document everything - Keep pay stubs and records to support your claim
File with correct amounts - If your employer won't correct it, file using the actual correct amounts and attach a note
Keep the original T4 - CRA may ask for documentation

Deadline: Employers must issue T4 slips by the last day of February following the tax year. If you haven't received yours by mid-March, contact your employer.

Multiple T4 Slips

If you had multiple employers during the year, you'll receive a T4 from each one. When filing:

Report income from all T4s on your return
Add up all Box 14 amounts for total employment income
Check for CPP/EI overpayments if your total income exceeds maximum pensionable/insurable earnings

T4 vs Other Tax Slips

Slip	Purpose
T4	Employment income from an employer
T4A	Pension, retirement, annuity, self-employment commissions
T4E	Employment Insurance benefits
T5	Investment income (interest, dividends)

Key Takeaways

Box 14 shows your total taxable employment income
Box 22 shows how much tax was already withheld
Boxes 16 and 18 show your CPP and EI contributions (which are tax credits)
Box 52 (Pension Adjustment) affects your RRSP room
Contact your employer immediately if any amounts seem incorrect

Need Help With Your Taxes?

Our AI tax assistant can help you understand your T4 and answer specific questions.

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Disclaimer: This guide is for educational purposes. For specific questions about your T4, consult the CRA or a qualified tax professional.

What is a T4 Slip?