T4 Slip in Canada 2025: Understanding Every Box, Common Errors, and How to Request a Correction

Every Canadian employee receives at least one T4 slip each tax season, yet few people understand what all those numbered boxes actually mean — or what to do when something looks wrong. Whether you are filing your own return or handing documents to an accountant, knowing how to read your T4 slip can save you money, prevent CRA delays, and help you catch errors before they become problems.

What Is a T4 Slip?

A T4 slip, formally called the Statement of Remuneration Paid, is the document your employer must provide by February 28 of the following tax year. It summarises every dollar of employment income you received during the calendar year and every statutory deduction taken from your paycheques. Your employer sends one copy to you and files a corresponding T4 summary directly with the CRA. That means CRA already has your employment information on file before you even log into NETFILE — any discrepancy between what you report and what your employer reported will trigger a review or reassessment.

If you worked for more than one employer during the year, each employer issues a separate T4. All of them must be included when you file your T1 personal income tax return.

Box 14: Employment Income — The Starting Point

Box 14 is the single most important figure on your T4. It represents your total gross remuneration, which includes wages, salary, bonuses, commissions, tips, director fees, and the value of most taxable benefits your employer provided. Box 14 is the number that flows into line 10100 of your T1 return.

One common source of confusion is that Box 14 is larger than what you actually deposited into your bank account. That is by design. Taxable benefits — things your employer paid on your behalf that CRA treats as employment income — are added to Box 14 even though you never received cash. Your take-home pay was reduced by income tax, CPP, and EI withholdings, all of which appear separately in other boxes.

Key T4 Boxes You Need to Know

Beyond Box 14, the following boxes appear on most T4 slips and directly affect your tax return:

• Box 16 — CPP Contributions: The amount of Canada Pension Plan premiums deducted from your pay. For 2025, the employee CPP1 contribution rate is 5.95% on earnings between the basic exemption ($3,500) and the first ceiling ($71,300), for a maximum annual contribution of $4,034.10.
• Box 17 — CPP2 Contributions: The second CPP tier introduced in 2024 applies to earnings between the first and second ceilings. For 2025 the CPP2 rate is 4% on earnings up to the second ceiling of $81,900, for a maximum additional contribution of $432.00.
• Box 18 — EI Premiums: Employment Insurance premiums deducted. The 2025 employee EI rate is 1.64% on insurable earnings up to the annual maximum of $65,700, giving a maximum employee premium of $1,077.48.
• Box 22 — Income Tax Deducted: Federal and provincial income tax withheld at source. This is the figure CRA applies against your total tax owing when it processes your return.
• Box 24 — EI Insurable Earnings: Only appears if your EI insurable earnings differ from Box 14 — for example, if you received non-insurable payments such as certain severance amounts.
• Box 26 — CPP/QPP Pensionable Earnings: Only appears if your CPP pensionable earnings differ from Box 14.
• Box 40 — Other Taxable Allowances and Benefits: Taxable benefits not captured in their own dedicated box are reported here and are always included in Box 14.
• Box 44 — Union Dues: Union dues deducted from your pay. You claim these on line 21200 of your T1 for a deduction against income.
• Box 46 — Charitable Donations: Donations made through payroll deduction. You combine these with other donation receipts on Schedule 9.
• Box 52 — Pension Adjustment: Applies to members of a registered pension plan (RPP) or deferred profit sharing plan (DPSP). The pension adjustment reduces your RRSP deduction room for the following year because you already accumulated retirement savings through your employer plan.
• Box 38 — Stock Option Benefit: The taxable benefit arising from exercising employee stock options. This amount is included in Box 14.
• Box 67 — Retiring Allowance Eligible for RRSP: The portion of a retiring allowance that qualifies for a direct RRSP contribution based on pre-1996 service, bypassing your regular RRSP room.

Taxable Benefits: Why Your T4 Box 14 May Surprise You

Many employees are surprised to find their T4 Box 14 higher than expected. The reason is employer-provided taxable benefits. CRA requires that the following be included in your employment income and reflected in Box 14, often with a corresponding notation in Box 40 or another benefit-specific box:

• Group term life insurance premiums paid by your employer above $500
• Personal use of a company vehicle (a standby charge and operating expense benefit calculated using a CRA formula)
• Employer-paid parking in a commercial lot
• Interest-free or low-interest loans where the rate charged is below the CRA prescribed rate
• Personal use of an employer-provided cell phone or device beyond a reasonable allowance
• Gifts and awards from your employer exceeding $500 in a calendar year

These amounts are taxable income even though you received a perk rather than cash. Your employer is responsible for correctly valuing each benefit and including it on your T4.

Common T4 Errors to Watch For

Payroll mistakes happen more often than most people realise. Before you file your T1, compare your final pay stub of the year against each T4 box and look for:

• Wrong Social Insurance Number (SIN): A transposed digit means CRA cannot match the slip to your file, causing delays in processing your return.
• Incorrect address: Not a tax calculation issue, but it affects whether you physically receive the slip.
• Missing boxes: A taxable benefit your employer forgot to report will show up in CRA's system when they audit payroll, but not on your T4 — leaving you exposed to a future reassessment.
• Double-counted benefits: Some payroll systems include a benefit in both a specific box and Box 40, adding it twice to Box 14.
• Wrong income amounts: Particularly common after mid-year raises, retroactive pay adjustments, or lump-sum bonus payments processed separately.
• Incorrect CPP or EI calculations: If your employer applied the wrong rate or ceiling, your Box 16, 17, or 18 amounts will be off, affecting your tax balance and any overpayment credit you may be entitled to.

How to Request a T4 Correction

If you spot an error, start by contacting your employer's payroll department in writing. Keep a copy of your request. The employer must file an amended T4 with CRA if the error affects the tax figures, and provide you with a corrected copy.

Do not wait indefinitely for a corrected slip if your filing deadline is approaching. You can file your T1 using the correct amounts and attach a brief explanatory note. CRA will reconcile the discrepancy once the amended T4 is received. If your employer acknowledges the error but fails to act, or outright refuses to make the correction, call CRA at 1-800-959-8281. CRA can contact the employer directly and, in some cases, accept your documented figures.

What to Do If Your T4 Is Missing

Employers are required to issue T4 slips by February 28. If mid-March arrives and you still have not received yours, take the following steps:

1. Contact your employer's payroll or HR department directly.
2. If the employer is unreachable or unresponsive, call CRA at 1-800-959-8281 and request information slips. CRA receives the T4 summary filed by the employer and can provide the amounts on record.
3. You can also view T4 information through your My Account portal on the CRA website, typically available for the prior tax year by late February or early March.

Multiple T4 Slips and CPP Overpayment

If you changed jobs during the year or held more than one position simultaneously, you will receive a T4 from each employer. Include all of them when filing — CRA will compare the aggregate against its records.

One often-missed tax credit arises when multiple employers each deducted CPP contributions to the annual maximum independently. Because CPP is capped per employee — not per employer — you may have contributed more than the legal maximum across your combined slips. Any CPP overpayment is fully refundable and is claimed on line 44800 of your T1. Check this if you had two or more T4 slips in 2025; the credit can be several hundred dollars.

If you have questions about reading your T4, correcting an error, or ensuring all slips are accounted for before you file, the team at Swift Accounting Calgary is available year-round — not just during tax season. We work with employed individuals, business owners, and contractors across Alberta to make sure every number on every slip is right before it goes to CRA.

Contact Swift Accounting today to book a consultation or get a second set of eyes on your T4 slips before your filing deadline.

Frequently Asked Questions

When must my employer give me my T4 slip?

Your employer is required to provide your T4 slip no later than the last day of February following the tax year. For the 2025 tax year, that deadline is February 28, 2026. Employers who miss this deadline can face CRA penalties. If you have not received your T4 by mid-March, contact your employer first, then call CRA at 1-800-959-8281 if needed.

Why is my T4 Box 14 higher than the total on my pay stubs?

Box 14 includes the cash value of any taxable benefits your employer provided during the year — things like personal use of a company vehicle, employer-paid parking, or group life insurance premiums above the non-taxable threshold. These benefits are treated as employment income by CRA even though you never received them as cash, which is why Box 14 can be higher than your direct deposit total.

What happens if I file my taxes before my employer sends a corrected T4?

You can file using the correct amounts and include a brief written explanation with your return. CRA will match your filing against the amended T4 once the employer files it. You will not be penalised for filing on time with accurate figures, even if the corrected slip has not yet been issued. Keep all documentation — your original T4, any correspondence with your employer, and any calculations you used to arrive at the corrected amount.

Can I claim a refund if too much CPP was deducted from multiple employers?

Yes. Each employer is required to deduct CPP independently up to the annual maximum, but the maximum applies to you as an individual — not per employer. If your combined CPP contributions across all T4 slips exceed the 2025 employee maximum of $4,034.10 for CPP1 (plus up to $432.00 for CPP2), the overpayment is fully refundable. Claim it on line 44800 of your T1 personal income tax return. CRA will apply it as a credit against any balance owing or include it in your refund.