Updated Checked by the Tax-Services.ca editorial team How we check
Doing taxes online in Canada means sending your return through certified tax software over NETFILE, and for a 2025 return that door opened on February 23, 2026. Most people had to file and pay by April 30, 2026. Self-employed people had until June 15, 2026 to file, though any balance was still due April 30.
How do you file your taxes online?
The CRA keeps a list of certified software from outside companies. You pick one, enter your slips and answers, and the program does the sums and sends the return. To send it you use a NETFILE access code, which the software walks you through.
The list is sorted by cost and features, so give it five minutes before you type anything. We can’t tell you which product is cheapest or best, because we haven’t verified any prices and they change every year. Ask three things: does it cover your slips, does it handle your situation (rent, self-employment, a move between provinces), and does it charge you at the end or up front?
NETFILE stays open until January 29, 2027 for 2025 returns and older ones back to 2018. The next season’s dates for 2026 returns aren’t published yet.
What should you have on the table before you start?
Pull together your T4 from each employer, any T5 or T3 slips for interest and investments, your RRSP receipts, tuition slips, and last year’s notice of assessment. Sam in Halifax keeps a folder on the desktop called “tax stuff” all year, drops every slip in as it arrives, and finishes in an evening. Do that and you’ll never be hunting for a receipt at tax time.
You’ll also want your SIN, your date of birth, and the banking details for direct deposit. Have your spouse’s net income handy too if you’re filing as a couple, since some credits depend on it.
Are there free ways to do it?
Yes, and check them first if your income is modest. Really. The CRA lists SimpleFile, its free filing service for eligible people, which opened March 9, 2026 for lower incomes and simple tax situations. It also lists free tax clinics, where a volunteer prepares the return if your income is modest and your situation is simple. We couldn’t confirm the exact income limits, so read the CRA’s eligibility page before you book.
A paid preparer can send your return through EFILE instead. That’s a fee-for-service route, and fee levels vary too much for us to quote any.
Options at a glance
| Way to file | Who it suits |
|---|---|
| Certified software with NETFILE | Most people who are comfortable with forms |
| SimpleFile | Lower income, simple situation |
| Free tax clinic | Modest income, simple situation |
| Paid preparer with EFILE | Complicated files, or when you want it done for you |
| Paper return by mail | Anyone who prefers it, but it’s the slow way |
What does a mistake cost?
Filing late costs you when you owe money. The penalty on the 2025 return is 5% of the balance owing, plus 1% for each full month late, up to 12 months. If you were penalised in the last few years, it climbs to 10% plus 2% a month. Interest also builds daily from the day after the due date.
So a $2,000 balance filed four full months late carries a penalty of 9%, which is $180, before any interest. If you can’t pay in full, file anyway.
What will you get back?
Take an Ontario employee earning $70,000 with $13,000 of tax withheld from the paycheque. The tax refund calculator shows income tax of $11,133.91 and a refund of $1,866.09. Add a $5,000 RRSP deduction and tax drops to $9,651.41, so the refund becomes $3,348.59. Software would find the same deduction, but only if you type in the receipt, so keep the slip from your RRSP deposit somewhere you can find it in March, not buried under a year of email.
Before you start, run your rough numbers through the income tax calculator. Plan an RRSP deposit with the RRSP calculator, and see what else you can claim in the tax credits calculator (federal only).
Common slip-ups when filing online
Typing in a slip before all your slips have arrived is the classic. Most come by the end of February, and the CRA says to contact the issuer if one hasn’t turned up by the end of March. Another is skipping your CRA account, where you can check your return status, see your notice of assessment and pay a balance. It’s free, and once you’ve used it you’ll wonder why you ever waited on hold with the CRA.
Then there’s the refund date, and it needs its own warning. We couldn’t find a processing time on the CRA pages we read, so don’t plan a purchase around a promised day. Add direct deposit details to get the money faster than a cheque, and file early.
If you spot a mistake after you’ve sent the return, don’t file a second one. Wait for your notice of assessment, then ask the CRA to adjust the original. A duplicate return only muddies things.
The CRA also says eligible people will get invitations from March 2027 to use pre-filled returns sent directly from their account. That’s a plan, not something you can use now.
Sources, and how we checked them
Dates, penalties and filing options come from the Canada Revenue Agency‘s 2026 filing-season pages and its late-filing page. The refund examples come from this site’s calculators with 2026 tax data. We’re an independent site and have no tie to the CRA.
Frequently asked questions
What is NETFILE?
It's the CRA's service for sending a return over the internet from certified tax software. You need a NETFILE access code, which the software gives you.
Is there a free way to file online?
The CRA offers SimpleFile for eligible people with lower incomes and simple situations, and free tax clinics staffed by volunteers. Check the eligibility rules first.
When was the deadline for the 2025 return?
April 30, 2026 for most people. Self-employed people had until June 15, 2026 to file, but the balance was still due April 30.
What is the penalty for filing late?
5% of the balance owing plus 1% for each full month late, up to 12 months. A repeat penalty is 10% plus 2% a month.
Can I still file an older return online?
NETFILE accepts returns for 2018 to 2025 until January 29, 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