A T4, or Statement of Remuneration Paid, is an information slip prepared and issued by the employer that records how much employment income an individual was paid during a tax year and the amount of income tax that was deducted.

Understanding your obligations as well as those of your employers when it comes to this important starting point in the tax process is essential. Employers are required to file T4’s by the end of February each year. In turn, employees should receive one copy for your personal records and another that gets submitted with your income tax return to the government.

Remember, unless you’re a freelance worker or are under contract, you need to have a T4 for every place you’ve worked for the tax year. The length of time you spent with each of these firms doesn’t matter—if you don’t include these documents for each of the places you’ve worked when you file a return, you run the risk of being assessed by the Canada Revenue Agency.

Keep in mind, it’s illegal for an employer to withhold a T4 so if you work for an employer that’s attempting this, you need to take the necessary action so the CRA understands the nature of the issue.

There are options for filing your return when there’s trouble getting this essential documentation, but it’s important to keep in mind that issues with T4’s aren’t all that common with most employers.