When do I have to give employees their T4 slips and file with CRA in Ontario?

T4 slips summarize the employment income, CPP contributions, EI premiums, and income tax withheld for each employee during the calendar year. As an Ontario employer you must issue each employee their T4 slip and file the T4 Summary with CRA by the last day of February following the tax year. For example, T4s for the 2025 calendar year are due February 28, 2026.

You must provide the T4 to the employee — by mail to their last known address, electronically with their consent, or in person. The T4 Summary (a totals sheet) and the individual T4 slips are filed electronically if you have more than a handful of employees; CRA sets an annual threshold above which electronic filing is mandatory.

If an employee leaves during the year, you do not have to issue their T4 until the February deadline unless they ask for it sooner — in which case you have 30 days to provide it after receiving the written request. Penalties for late or incorrect T4 filings can add up quickly, especially if you have multiple employees.