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You file taxes online in Canada by using tax software the CRA has certified, and sending the return through NETFILE. For the 2025 tax year the deadline was April 30, 2026, or June 15, 2026 if you or your spouse is self-employed, though any balance owing was still due April 30. For the 2026 tax year the usual dates are April 30, 2027 and June 15, 2027.
What do you need to file taxes online?
Three things, and only the first takes any shopping. You need certified software, your slips and, if you have one, your NETFILE access code. The CRA’s NETFILE page says to use CRA-approved software, and the CRA publishes a list of certified products each tax year. Some products are free for modest incomes or simple returns, and others charge, so read each provider’s own page before you start typing.
| Item | What to know |
|---|---|
| Software | Must be CRA certified; free and paid versions exist |
| Access code | Optional; 8 characters, found on your latest notice of assessment |
| Filing deadline, 2025 return | April 30, 2026 |
| Self-employed filing deadline | June 15, 2026, balance still due April 30 |
| NETFILE window for the 2025 return | February 23, 2026 to January 29, 2027 |
| How long to keep records | At least six years |
Do you really need the access code?
No. The CRA’s get ready to file page says the access code isn’t mandatory. What you give up by leaving it blank is a shortcut: the CRA can’t use your most recent return to confirm your identity. Only the code on your newest notice of assessment works, and first-time filers won’t have one, so don’t let that hold you up.
When can you file the next return?
It’s November now, so the return you’ll file next is for 2026. The CRA hasn’t published its dates for that season that we could find, and we won’t guess them. Watch the CRA’s important dates page in the new year. Last season’s pattern was an opening on February 23 and a deadline of April 30, which is a hint and not a promise.
One useful detail: the 2025 return can still go through NETFILE until January 29, 2027. If you missed it, file now. Any balance owing keeps costing you interest, and benefit payments such as the GST/HST credit and Canada child benefit may be held up when a return is missing.
How do you file with certified software, step by step?
Pick a certified product and create an account. Enter your slips, answer the questions about your year, and let the software total everything. Read the summary page before you send it, because that page is where a wrong province or a duplicated slip shows up. Then submit through the software, with your access code if you have it, and keep the confirmation.
The CRA sends a notice of assessment after it processes the return. It tells you if you’re due a refund, owe a balance or neither, and it also carries figures you’ll want next year, such as your RRSP room. Save it with the rest of your records, since that’s also where next year’s access code lives.
What will you owe or get back?
Do this before you open the software, because a surprise is easier to spot when you have a rough number. Say you’re in Ontario on a $60,000 salary. The income tax calculator gives $8,320.50 of federal and Ontario tax.
Your slip shows how much your employer already sent in. If it’s $9,500, the tax refund calculator shows a refund of $1,179.50. If only $7,000 was withheld, you’d owe $1,320.50. Your software may land somewhere different, since it also counts credits the calculator leaves out. The tax credits calculator shows how deductions and credits move the total, though it’s federal only.
Can you file a past or amended return online with NETFILE?
Yes, for several years back. The CRA says NETFILE is open from February 23, 2026 until January 29, 2027, and that you can use it to send your initial personal income tax and benefit return for 2018 through 2025. The ReFILE service covers amended T1 returns for 2022, 2023, 2024 and 2025.
Both services work through CRA certified tax software, so the steps match the ones above. Check that the software you pick lists the tax year you need, because each product decides which years it supports.
Where do returns go wrong?
Most errors are dull. A slip is missing because it arrived late or by email. The province is wrong, and provincial tax follows where you lived on December 31. Direct deposit details are old. And people forget that the June 15 date for self-employed filers doesn’t move the payment date.
Self-employed, or paid with no tax withheld? Then the tax instalments calculator shows if you should have been paying during the year. That’s a bill you can plan for, unlike the surprise of a lump sum in April.
Should you hire someone instead? For a simple return it’s rarely needed, and the CRA lets a preparer file for you electronically for a fee if your situation is complicated. You’re still responsible for what’s on the return.
What if you can’t pay what you owe?
File anyway, and on time. Filing late adds a separate problem to the payment problem, and the software will happily send a return showing a balance owing. Pay what you can, and contact the CRA about the rest rather than waiting for a letter. Sam in Regina, with a $1,320 balance and a tight month, is better off filing on April 30 than waiting until the money turns up.
From March 2027 the CRA plans to invite about 1 million people to a pre-filled 2026 return in their CRA account. From February 22, 2027, signing in to your CRA account when you file online becomes an optional step. The conditions and income limits are in CRA Pre-Filled Tax Return 2027: Who Gets an Invitation.
Where do these dates and rules come from?
The filing dates, the NETFILE window, the certified software rule and the free software note come from the Canada Revenue Agency‘s pages, read in October 2026. The tax figures come from the 2026 rates behind our calculators. No government body has reviewed or endorsed what you read here.
Frequently asked questions
What do I need to file taxes online in Canada?
You need CRA certified tax software, a NETFILE access code and your tax slips.
What was the deadline for the 2025 return?
It was April 30, 2026, or June 15, 2026 for self-employed people, with any balance still due April 30.
Is there free software?
Some certified software is free for modest incomes or simple returns. Each provider's page says who qualifies.
Can I still file the 2025 return online?
Yes. The NETFILE window for it runs until January 29, 2027.
- How to file your tax return in Canada: steps and dates
What to gather, when your return is due and how to file in Canada, from the first slip to the notice of assessment that closes the year