T4 Filing Guide for Self-Incorporated Canadians

If your corporation paid you a salary during the year, you must issue yourself a T4 slip and file a T4 Summary with CRA by the last day of February. Here's how to do it right.

What is a T4?

A T4 (Statement of Remuneration Paid) is the Canadian equivalent of a W-2 in the US. It summarizes the employment income your corporation paid you during the calendar year, and all the deductions that were withheld. You need it to file your personal tax return.

As the only employee of your corporation, you're both the employer (filing the T4) and the employee (receiving it). CRA expects you to play both roles correctly.

T4 filing deadline

The T4 slip and T4 Summary must be filed with CRA and distributed to the employee (you) by the last day of February following the tax year. For the 2025 tax year, that's February 28, 2026.

Late filing penalties start at $100 minimum and increase based on the number of slips and delay duration.

Key T4 boxes for self-incorporated Canadians

Box 14 — Employment income: Your total gross salary paid during the year. This is the sum of all your paystub gross amounts.

Box 16 — Employee's CPP contributions: The total CPP withheld from your paycheques. In 2026, the maximum is $4,034.10.

Box 17 — Employee's QPP contributions: Only if you're in Quebec (QPP instead of CPP).

Box 18 — Employee's EI premiums: The total EI withheld. In 2026, the maximum is $1,077.48.

Box 22 — Income tax deducted: The total federal income tax withheld across all pay periods.

Box 26 — CPP/QPP pensionable earnings: Usually the same as Box 14 minus the basic exemption portion that wasn't subject to CPP. Often equals Box 14 for simplicity if it's within the maximum.

Box 24 — EI insurable earnings: Total earnings subject to EI, up to the annual maximum ($65,700 in 2026).

Box 52 — Pension adjustment: Only relevant if you have a registered pension plan. Most self-incorporated owners leave this blank.

How paystubs feed into T4 accuracy

Your T4 numbers come directly from your payroll records — specifically your paystubs. Box 14 is the sum of gross pay on all paystubs. Box 16 is the sum of CPP deductions. Box 18 is the sum of EI deductions. Box 22 is the sum of federal tax withheld.

If your paystubs were calculated correctly throughout the year — using the right CRA rates for each pay period — your T4 numbers should add up cleanly. If you've been estimating deductions or keeping sloppy records, the T4 preparation becomes much harder.

This is the practical reason why accurate paystubs matter. They're not just for show — they're the source documents your T4 is built from.

T4 Summary

The T4 Summary (RP-0003) is the employer-level filing that aggregates all T4 slips. For a one-person corporation, there's only one slip — yours. The Summary reports total employment income, total deductions, and total remittances made to CRA during the year.

File the T4 Summary online through CRA's My Business Account or through payroll software. You can also mail paper copies, but CRA strongly prefers electronic filing.

Employer CPP and EI

Remember that as the employer, your corporation also owes: - Employer CPP: equal to the employee CPP (another $4,034.10 maximum in 2026) - Employer EI: 1.4x the employee EI ($1,508.47 maximum in 2026)

These employer amounts are not on the T4 — they're a corporate expense tracked separately. They should have been remitted to CRA throughout the year along with the employee deductions.

Record keeping

Keep your T4s and supporting paystubs for at least six years. CRA can reassess up to three years back under normal circumstances, and longer if there's suspected fraud.

A clean set of PDF paystubs for each pay period, organized by year, is the simplest approach. Generate them at the time of payment — don't reconstruct them later.