When you receive a financial disclosure request, you may be asked to provide your income tax returns, T4 slips and Notices of Assessment for the last several years. Because these documents all relate to income and taxes, it is easy to assume that they contain the same information.
Each document has a different purpose, and one cannot always replace another. Understanding the difference can help you provide the correct records and avoid repeated requests.
What Is a T4 Slip?
A T4 slip is prepared by an employer after the end of the calendar year. It shows the employment income the employer paid you during that year and the amounts deducted from your pay.
A T4 commonly includes your employment income, income tax deducted, Canada Pension Plan contributions and Employment Insurance premiums. It may also include pension contributions, union dues or other employment-related amounts.
If you worked for more than one employer during the year, you may receive a separate T4 from each employer. You may also receive other tax slips, such as a T4A, for pension payments, fees, commissions, scholarships or certain other types of income.
A T4 provides information about income from one employer. It does not necessarily show all the income you received during the year.
What Is an Income Tax Return?
Your personal income tax return is the complete tax filing submitted to the Canada Revenue Agency for a particular year. It is often called a T1 General or simply a tax return.
The return brings together information from your T4 slips and other sources. It may include employment income, self-employment income, rental income, investment income, pensions, benefits and other amounts.
It also contains information about deductions, credits, dependants and taxable income. Because it includes more than employment income, the tax return usually presents a broader picture of your financial circumstances than a T4 alone.
A copy may be available through the tax software used to prepare the return, from your accountant or tax preparer, or in the records you saved when the return was filed.
What Is a Notice of Assessment?
A Notice of Assessment is issued by the Canada Revenue Agency after your income tax return has been reviewed and processed.
The Notice of Assessment summarizes important information from your return, including your total income, net income, taxable income, tax payable, refund or balance owing. It may also show your available Registered Retirement Savings Plan contribution room.
If the Canada Revenue Agency changes your return after it was assessed, it may issue a Notice of Reassessment. When a financial disclosure request asks for Notices of Assessment, you should check whether a more recent Notice of Reassessment exists for the same year.
Notices of Assessment and Reassessment can generally be accessed through your Canada Revenue Agency account.
Why Might All Three Be Requested?
Each document provides a different part of the income picture.
A T4 confirms employment income reported by a particular employer. The income tax return shows the different types of income, deductions and credits that you reported. The Notice of Assessment shows how the Canada Revenue Agency processed and assessed that return.
Looking at the documents together can help confirm whether the income figures are complete and consistent. It can also identify other income sources that may not appear on a T4.
For this reason, submitting only a Notice of Assessment may not satisfy a request for a complete income tax return. Similarly, providing only a tax return may not satisfy a separate request for your T4 slips.
Make Sure You Provide the Correct Years
Before submitting the documents, check the tax years requested. A request for the last three years usually means that you should provide the tax return, relevant tax slips and Notice of Assessment for each of those years.
Make sure the year shown on each document is clear and that every page of the income tax return is included. If a Notice of Reassessment was issued, include it with or instead of the earlier Notice of Assessment, depending on the request you received.
Clear filenames can make the documents easier to organize. For example, you could use “2025 Income Tax Return,” “2025 T4” and “2025 Notice of Assessment.”
Understanding the role of each document makes it easier to respond accurately and helps reduce delays caused by incomplete or incorrect records.
This article provides general educational information and is not legal advice. If you are uncertain about which tax documents you must provide or how the information may affect your situation, consider speaking with a family law professional or an appropriate court support service.
