Updated Checked by the Tax-Services.ca editorial team How we check
A tax declaration in Canada means filing your annual income tax and benefit return with the CRA. For 2025 income, most people had to file and pay by 30 April 2026, and self-employed people had until 15 June 2026 to file. The payment date stayed at 30 April even for them. Dates for the 2026 return aren’t published yet, so check the CRA page in early 2027.
When is the tax declaration due?
| Who you are | File by | Pay by |
|---|---|---|
| Most individuals, 2025 return | 30 April 2026 | 30 April 2026 |
| Self-employed, or spouse of one, 2025 return | 15 June 2026 | 30 April 2026 |
| Any due date on a weekend or CRA holiday | Next business day | Next business day |
If you missed the 2025 deadline, file now anyway. Late filing can bring interest and penalties, and it can hold up benefit payments such as the GST/HST credit, the Canada child benefit and Old Age Security. The sooner the return is in, the sooner those payments can start again.
Do you have to file if you earned very little?
Not always, but it often pays to. Picture Dana, a student in Hamilton who made $4,000 at a summer job. She may owe nothing, yet a filed return is what lets the CRA work out credits and benefit payments for her. If you got a notice from the CRA asking for a return, you must file regardless.
A simple rule: if you owe tax, had tax withheld that you’d like back, or want benefits and credits, file.
What do you need before you start?
Your slips, mostly. That means a T4 from each employer, T5 slips for interest or dividends, and receipts for anything you plan to deduct, plus last year’s notice of assessment, which shows your RRSP room. Gather all of it before you open the software, because stopping halfway to hunt for a slip is how returns end up late.
Count the slips against your jobs and accounts for the year. One missing T4 means a wrong return.
How do you file the return?
Most people use CRA-certified software and send it through NETFILE. For the 2025 return the service opened on 23 February 2026 and stays open until 29 January 2027. Paper returns are still accepted by the CRA, but most people find the online route quicker to finish and easier to fix when a number is wrong.
Not sure you’d pay anything? Some certified programs charge nothing for a simple return. We cover how to check that in our guide on filing for free.
Will I get a refund or owe tax?
Take an Ontario employee earning $60,000 with $8,500 of income tax withheld on the T4. The tax refund calculator puts the tax for the year at $8,320.50, so the refund is $179.50.
Now add a $3,000 RRSP contribution. Tax falls to $7,566.72 and the refund grows to $933.28. That’s $753.78 more for a $3,000 deposit. Try your own numbers in the RRSP calculator to see what it does over time.
A refund isn’t a gift. It’s your own money coming back because too much tax came off your cheques during the year, so a fat refund at tax time mostly means you lent the taxman a few hundred bucks for free. A balance owing is the reverse: too little came off. Neither is good or bad on its own, and the size of the gap is what tells you whether your withholding is about right.
The income tax calculator shows the bill before credits you add yourself, so treat any figure as an estimate and let the software give the final number.
Mistakes people make on a declaration
Using the wrong province. Your tax follows where you lived on 31 December, not where you worked.
Forgetting that a balance owing isn’t pushed back for the self-employed. The 15 June date is for filing only.
Leaving out side income. Cash jobs, rental income and online sales all belong on the return, and the self-employed can work out what they’ll owe in our self-employed tax calculator. Our tax credits calculator only covers federal amounts, so look up your province’s credits on top.
And skipping the return because you earned little. The CRA warns that a late return can interrupt benefit payments, so filing even a low-income return is the safer choice.
Sources, and how they were checked
Dates come from the Canada Revenue Agency‘s pages on filing due dates for the 2025 tax return and on NETFILE. The examples use our 2026 federal and Ontario tax data, so the return you file for 2025 income will differ slightly. A late filing penalty amount couldn’t be confirmed on the pages read, so it isn’t stated here. This site is independent and has no link to the CRA.
Frequently asked questions
What is a tax declaration in Canada?
It's your annual income tax and benefit return, sent to the CRA. It reports your income for the year and works out whether you get a refund or owe tax.
When is the tax declaration due?
For the 2025 return, 30 April 2026 for most people and 15 June 2026 for the self-employed. Any tax owing was still due on 30 April.
Should I file if I earned very little?
Yes, in most cases. The CRA says late filing can disrupt benefits such as the GST/HST credit and the Canada child benefit.
Can I file my return online?
Yes. NETFILE, used through CRA-certified software, is open from 23 February 2026 to 29 January 2027 for the 2025 return.
What is the 2026 filing date?
It isn't published yet. Check the CRA's filing due dates page before you plan around 30 April 2027.
- How Canadian income tax works: brackets and credits
How federal and provincial Canadian income tax stack up, what marginal and average rates mean, and how credits and deductions change your bill