T4, in plain English.

February 28 is not a soft deadline.

Miss the T4 filing window and the Canada Revenue Agency has a formula for what comes next. For a payroll team carrying hundreds of employees through year-end, late T4 slips carry real weight.

What the T4 captures.

The T4, formally the Statement of Remuneration Paid, is the year-end slip every Canadian employer issues to each employee and files with the Canada Revenue Agency. It reports employment income alongside every major deduction withheld across the calendar year: Canada Pension Plan contributions, CPP2 (the second additional contribution), Employment Insurance premiums, and federal income tax withheld. One slip per employee. The same obligation covers every worker on the payroll, from a part-time hire to a senior executive.

Both parties get a copy. The CRA uses it to verify what was remitted against the employer's reported totals. The employee relies on it to complete their annual return. When those copies tell the same story, the year is closed. When they do not, the CRA takes notice.

How the T4 is filed.

The filing deadline is the last day of February following the calendar year. An employer reporting on the 2025 tax year must file by February 28, 2026. Employees receive their copies by the same date.

Employers submit the slips directly to the Canada Revenue Agency. Each slip covers one employee's full-year figures. The CRA cross-references those figures against the remittances made throughout the year. A gap between what was withheld, what was remitted, and what the T4 shows is the kind of discrepancy that invites a review.

Mistakes that show up in audits.

• CPP and CPP2 reported as a single figure. The second additional CPP contribution is a separate amount from the base Canada Pension Plan contribution. Treating them as one combined total understates what was withheld in each category and produces a mismatch in CRA records.
• Amended slips never issued. A payroll correction processed after the original T4 was distributed requires an amended slip. Leaving the original in place means two versions of the year coexist: the employer's and the employee's. The CRA receives both if the employee files using the uncorrected copy.

What Workzoom calculates.

Workzoom has run Canadian payroll since 2001. Twenty-five years of CPP tables, EI rate changes, and year-end filing cycles. Family-owned, founder still leading it.

Workzoom calculates CPP, CPP2, EI premiums, and income tax on every pay run and generates T4 slips for the employer to submit and remit to the Canada Revenue Agency. No export step between systems. Because HR, time, and payroll share one database, the figures that populate the T4 are the same figures that drove every pay run across the year. No reconciliation between modules built separately and stitched together later.

County of Renfrew, an Ontario municipality, and Silvera for Seniors run Canadian payroll on Workzoom. For organizations where year-end accuracy is not optional, that single database is the whole point.