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The T4 filing requirements come down to one date. You file the T4 slips and the T4 Summary with the CRA, and hand each employee a copy, by the last day of February after the year in question. For 2025 slips the deadline was March 2, 2026, because February 28 fell on a weekend.
Do you have to issue a T4?
If you paid someone employment income, you probably do. The CRA says an employer, resident or not, must issue a T4 when any one of these is true: you deducted CPP or QPP, EI or income tax; you paid the worker more than $500 in total; or you gave a current employee taxable group term life insurance.
A T4 covers salary, wages, bonuses, taxable benefits and retiring allowances. Some payments go elsewhere. Pensions use a T4A, payments to non-residents use a T4A-NR, and construction subcontractor payments don’t go on a T4 at all.
What do the boxes on a T4 mean?
A handful of boxes cause most of the mistakes.
| Box | What it shows |
|---|---|
| 14 | Employment income before deductions |
| 16 | Employee CPP contributions |
| 17 | Employee QPP contributions |
| 18 | Employee EI premiums |
| 22 | Income tax deducted |
| 26 | CPP or QPP pensionable earnings |
| 44 | Union dues, when the union doesn’t issue receipts |
| 46 | Charitable donations deducted |
| 52 | Pension adjustment |
The T4 Summary adds up all your slips. Its totals should match both the slips and what you remitted during the year.
What happens if you file late?
The penalty grows with the number of late slips, according to the CRA employers’ guide.
| Slips filed late | Penalty per day | Maximum |
|---|---|---|
| 1 to 50 | $10 | $1,000 |
| 51 to 500 | $15 | $1,500 |
| 501 to 2,500 | $25 | $2,500 |
| 2,501 to 10,000 | $50 | $5,000 |
| 10,001 or more | $75 | $7,500 |
That’s separate from a $25 a day charge for each slip you didn’t give an employee, with a $100 minimum. And if you file more than five information returns, the guide says you must file them online. Paper gets its own penalty.
Note that when the last day of February lands on a Saturday or Sunday, the next business day is your deadline.
What does one year of payroll look like on a T4?
Take an Ontario employee on $75,000, paid every two weeks. That’s $2,884.62 a period. The payroll deductions calculator shows $317.64 of federal tax, $171.00 of Ontario tax, $163.33 of CPP and $43.20 of EI each period.
Multiply by 26 and the slip would read roughly $75,000 in box 14, about $12,705 in box 22, about $4,247 in box 16 and about $1,123 in box 18. Treat those as estimates. Payroll software works in steps, and CPP and EI stop at their yearly maximums, so a real slip can be a few dollars off.
What does it cost the business? The payroll remittance calculator shows the employer matching the CPP and paying 1.4 times the employee’s EI on top. The Summary reports the total.
Mistakes that trigger a CRA letter
Filing late is the expensive one, and it usually happens because year-end checks start in February. Start in January. Confirm every name, social insurance number and address before you file.
Then there are mismatched totals. If the slips don’t add up to the Summary, or to what you paid the CRA during the year, expect questions. You can amend, add, replace or cancel a slip after filing, so fix a mistake the day you spot it.
Employees can use the slip as a check too. Compare box 14 with your last pay stub, then look at the CPP calculator and the EI calculator to see if the deductions look right. A big year-end payment? The bonus tax calculator explains why the tax on it looks high.
Where the numbers come from
Deadlines, boxes and penalties come from the Canada Revenue Agency’s pages on the T4 slip and its employers’ guide for filing the T4 slip and summary, read in September 2026. Example figures come from this site’s calculators. We have no link with the CRA or any government, and penalties can change, so check the current amounts before you file.
Frequently asked questions
When are T4 slips due?
The T4 return and the copies for employees are due by the last day of February after the calendar year. A weekend date moves to the next business day.
Who must issue a T4 slip?
An employer who paid employment income and deducted CPP, EI or tax, paid more than $500, or gave taxable group term life insurance.
What is the penalty for filing T4s late?
For 1 to 50 slips it is $10 a day up to $1,000. Larger volumes pay more, up to $7,500.
Do I have to file T4s online?
The CRA guide says an employer filing more than five information returns must file electronically, and a penalty applies otherwise.
What does box 22 on a T4 show?
Box 22 shows the income tax deducted from the employee during the year.
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Information only. This page is general information, not tax, legal or accounting advice. Tax-Services.ca is an independent publisher: we don't prepare or file tax returns or offer tax services, and we have no connection with the CRA, Revenu Québec, any government or any company named on this page. Check the figures that matter with an official source or a qualified professional.