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Tax prep for a simple return is mostly a paper chase, and once your slips are in a pile the filing itself can be short. For the 2025 return, online filing opened on 23 February 2026, and the deadline for most people was 30 April 2026. The 2026 dates aren’t published yet, so check the CRA page before you plan around them.
What do you need before you start tax prep?
Slips first. The CRA says most are issued by employers and financial institutions by the end of February. Expect a T4 from a job, a T4A for pensions and some other income, and a T5 for investment income.
If one is missing, look in your CRA account. The CRA says you can no longer request paper copies by phone, so use your account or ask the issuer.
Then the smaller things people forget: receipts for tuition, medical costs and donations, your updated address and direct deposit details, and last year’s notice of assessment. The CRA also suggests updating your personal information in your account before you file.
A simple tax prep timeline
| When (2025 return) | What happens |
|---|---|
| End of February 2026 | Most slips are issued |
| 23 February 2026 | Online filing opened |
| 30 April 2026 | Deadline for most people, and payment date for any balance |
| 15 June 2026 | Filing deadline if you or your spouse or partner is self-employed |
| 29 January 2027 | NETFILE, per the CRA, is open for the 2025 return until this date |
That last row is a filing window for late returns, not a reason to wait. The self-employed date moves the filing, not the payment.
How much will you get back or owe?
You can guess before you open any software. Say you’re single in Ontario, earn $52,000 from one job, and your T4 shows $7,500 of income tax withheld. The tax refund calculator puts your income tax for the year at $6,625.43. That leaves a refund of $874.57.
Now put $3,000 into an RRSP and deduct it. The same tool gives tax of $6,032.68, so the refund becomes $1,467.32. The contribution saved $592.75. If you’re weighing that, the RRSP calculator looks at it over the long run.
These are estimates. Credits the tool doesn’t cover, such as tuition, medical costs or donations, would raise the refund. Your income tax result is where to start.
Filing yourself or paying someone?
Your call, and often it’s easy. If your income is slips only, do it yourself. The CRA certifies tax software for NETFILE, and it says those companies aren’t CRA representatives. Some products have a free version, with conditions the provider sets.
You need your 8-character NETFILE access code, which the CRA says you can find in My Account. Since February 2026 the CRA also asks for a backup sign-in method, such as a passcode grid or authenticator app, so set that up before deadline week.
If your year was more tangled, a paid preparer or a free clinic may suit you better. We can’t tell you what preparers charge.
Mistakes people make with tax prep
Filing without every slip comes first. Even a small missing one can mean a corrected return later, so hunt it down now, in your account or from the issuer, and wait for it rather than guessing at the amount.
Then there’s the payment. Filing late is one cost, and the late-filing penalty is 5% of the balance owing plus 1% per full month, up to 12 months. On $1,000 owing and three full months late, that’s $80 before interest. If you can’t pay, the CRA still wants the return filed on time.
Throwing paper away is the third. Keep slips and receipts for at least 6 years.
The last is trusting the pay-stub number. Your employer’s withholding is a guess, and your return is the answer, so the take-home pay calculator is a better check than last year’s memory.
Where the numbers come from
The dates, slip timing, NETFILE details and penalty rules come from Canada Revenue Agency pages, read in September 2026. The refund examples come from our calculators, which use 2026 federal and Ontario tax data. This site has no link with the CRA or any government.
Frequently asked questions
When do I need to file my tax return?
For the 2025 return the deadline was 30 April 2026 for most people, and 15 June 2026 if you or your spouse was self-employed. We couldn't find the 2026 return dates yet.
Which slips do I need?
Commonly a T4 from a job, a T4A for pensions and some other income, and a T5 for investment income. Most are issued by the end of February.
Where do I find my NETFILE access code?
The CRA says it's in My Account, under your tax returns. It's 8 characters long.
How long should I keep my records?
The CRA says at least 6 years for slips, receipts and any completed Form T183.
What if I can't pay what I owe?
File on time anyway. The late-filing penalty is 5% of the balance owing plus 1% per full month, up to 12 months.
- 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
Information only. This page is general information, not tax, legal or accounting advice. Tax-Services.ca is an independent publisher: we don't prepare or file tax returns or offer tax services, and we have no connection with the CRA, Revenu Québec, any government or any company named on this page. Check the figures that matter with an official source or a qualified professional.