How and when do I issue T4 slips?

When T4s are due, to employees and to the CRA

The deadline for T4 slips is the same whether the recipient is your employee or the CRA: the last day of February following the calendar year the slip covers. A T4 for the 2026 calendar year, for example, is due by the end of February 2027, both as a copy given to the employee and as a filing submitted to the CRA. There is no separate, later deadline for one over the other.

Missing this date exposes an employer to late-filing penalties on the information return itself, on top of any separate exposure for late remittances during the year. Employers should build the T4 preparation timeline backward from this date rather than treating it as a task that only starts once February arrives.

A useful way to think about the timeline is to treat mid-January as the real starting point, not late February. That gives time to reconcile the year’s payroll register against remittances actually made, correct any pay run errors discovered along the way, and confirm taxable benefits from earlier in the year, such as a company vehicle or a holiday gift over the CRA’s limit, have actually been added to the right employee’s income before the slips are generated.

The boxes that matter most on a T4

A T4 slip reports several figures in specific numbered boxes, and getting each one right matters because the CRA cross-checks them against other filings. Box 14 shows total employment income; boxes 16 and 17 show CPP and QPP contributions; box 18 shows EI premiums; box 22 shows income tax deducted; boxes 24 and 26 show insurable and pensionable earnings, which are not always the same figure as box 14.

• Box 40 captures the value of taxable benefits included in the employee’s income for the year.
• Boxes 44 and 46 report union dues and charitable donations withheld through payroll.
• Box 52 reports the pension adjustment where the employee participates in an employer pension plan.

The T4 Summary: what it is and why it has to reconcile

The T4 Summary is filed alongside the individual T4 slips and totals everything across all employees for the year: total employment income, total CPP, EI, and income tax withheld, and the corresponding employer contributions. These totals need to match the sum of every individual T4 slip filed for that employer, since the CRA uses the Summary as a reconciliation check against the detailed slip data.

The Summary also serves as a check against what was actually remitted throughout the year. A mismatch between what the Summary says should have been withheld and what was actually remitted is one of the more common triggers for CRA follow-up, separate from any issue with an individual employee’s slip; our answer on payroll remittance due dates covers the ongoing side of this reconciliation.

It is worth distinguishing a T4 from a T4A here as well, since the two are easy to confuse on sight. A T4 reports employment income for someone on payroll as an employee, while a T4A generally reports fees paid to a contractor or certain other kinds of payments outside an employment relationship; a business that issues both types of slips needs a clear internal rule for which vendor gets which one.

Why electronic filing is now mandatory for most employers

Employers filing more than five T4 slips for a calendar year are required to file electronically, using the CRA’s Internet file transfer service or a payroll platform that files on the employer’s behalf, rather than mailing paper slips. Filing on paper when electronic filing is required can itself trigger a penalty, separate from any issue with the accuracy of the information reported.

Most payroll software built for the Canadian market, including the platforms covered in our answer on choosing payroll software, files T4s electronically as part of the year-end process automatically, which removes this as a manual step for most small employers.

An employer with five or fewer slips is not required to file electronically, but doing so anyway is generally worthwhile once the software already supports it, since it removes the risk of a paper filing arriving late through the mail or being misplaced before it reaches the CRA.

PIER reviews, amendments, and how we handle year-end filing

The CRA runs a Pensionable and Insurable Earnings Review, generally referred to as PIER, comparing the earnings and CPP or EI amounts reported on filed T4s against what should have been withheld based on the reported earnings. A mismatch generates a PIER letter asking the employer to explain or pay a shortfall, and it usually reflects a calculation error somewhere in the payroll process rather than deliberate wrongdoing.

If an error is discovered after slips have already been filed, whether from an internal review or a PIER letter, the correct fix is an amended T4 for the affected employee showing the corrected figures, rather than an informal adjustment on next year’s slip. Keep both the original and the amended slip on file, since an employee may need to explain the correction to the CRA when their own personal return is reviewed. We prepare year-end T4s and the T4 Summary for our payroll clients as a standard part of the payroll cycle, reconciling remittances against the Summary before filing rather than after a CRA letter raises the question. Our payroll services cover this year-end filing alongside ongoing remittance management.

Source: CRA — Payroll.