The T4 slip reports employment income and payroll deductions for use on the personal return.
A T4 slip is the Statement of Remuneration Paid, the main Canadian slip used to report employment income and related payroll amounts.
For many taxpayers, the T4 is the most important tax document of the year because it ties wages, payroll deductions, and employment reporting together in one place.
A T4 generally reports employment income paid by an employer along with related amounts such as income tax deducted, CPP contributions, and EI premiums. It feeds directly into the personal return and also reflects the payroll-reporting side of the employer’s obligations.
That is why the T4 sits at the intersection of two workflows:
Some T4 boxes are especially important because they connect directly to the taxpayer’s filing workflow:
| Common T4 box | What it usually reports | Why it matters on the return |
|---|---|---|
| Box 14 | Employment income | This is the core employment-income amount for the year |
| Box 22 | Income tax deducted | This helps determine the credit for tax already withheld |
| Boxes 16 and 17 | CPP/QPP contributions | These feed the CPP/QPP contribution calculation and claim |
| Box 18 | EI premiums | This supports the EI premium claim and overpayment check |
| Box 44 | Union dues | This can point to a deduction claim on the return |
| Box 45 | Employer-offered dental benefits code | This supports Canadian Dental Care Plan administration and is not entered as income |
The CRA’s individual T4 instructions also make clear that a T4 is not just about gross wages. It carries payroll deduction information and several boxes that point to later lines, schedules, or worksheets on the return.
A salaried employee may use the T4 slip to confirm employment income and payroll deductions before filing the T1 return. If the amounts are wrong, the issue may need to be corrected before or during filing.
A T4 slip is not the return itself.
It is also not used for every type of income. Other slips, such as T4A or T5, may apply when the payment type is different.
In Quebec-sensitive situations, it is also important not to collapse the T4 into the Releve 1 Slip. They can be related without being the same document.
It is also not only an “income” slip. Several T4 boxes describe deductions, pension adjustments, or employer-reporting details that affect other parts of the tax workflow.
Why is the T4 closely connected to payroll tax terms? Answer: Because it reports employment income together with payroll deductions such as income tax, CPP, and EI amounts.
Does every tax slip reporting payment from work have to be a T4? Answer: No. Other income situations can use different slips, such as a T4A.
Special boxes, employer corrections, and province-sensitive payroll details can create exceptions, so disputed or unusual T4 reporting should be checked against the current CRA instructions.