To file a Canadian income tax return, gather your slips and receipts, choose a filing method, enter your information, claim deductions and credits, then submit it electronically through NETFILE or mail a paper return. Most people file and pay by April 30. Filing your T1 return each spring settles your tax for the year and also sets your benefits: the CRA uses the income on your return to work out payments such as the Canada Child Benefit and the Canada Groceries and Essentials Benefit (formerly the GST/HST credit), and to calculate next year’s RRSP room.
What you need before you start
Income slips
| Slip | What it reports |
|---|---|
| T4 | Employment income and deductions |
| T4A | Pension, annuity, or other income |
| T4E | Employment Insurance benefits |
| T5 | Investment income (interest, dividends) |
| T3 | Trust income (mutual fund distributions) |
| T5008 | Securities transactions (buy/sell) |
| T2202 | Tuition amounts |
| T4RSP / T4RIF / T4FHSA | Withdrawals from registered plans |
Most slips are available in CRA My Account by mid-March. The guide to tax slips and documents explains what each box means.
Receipts and records
- RRSP contribution receipts
- Charitable donation receipts
- Medical expense receipts
- Moving expense receipts
- Child care expense receipts
- Employment expense records, if your employer signed a Form T2200
- Benefit letters
Last year’s Notice of Assessment
It shows your RRSP deduction limit, unused tuition amounts and other carry-forward balances. The guide to reading a Notice of Assessment explains each section.
How to file your taxes, step by step
Step 1: Choose a filing method
| Method | Who it suits |
|---|---|
| NETFILE-certified software (free and paid versions) | Most people, from a single T4 to investments and self-employment |
| A free volunteer tax clinic or the CRA’s SimpleFile service | People with modest income and a simple return |
| A paper return | People who can’t or prefer not to file online |
| An accountant or tax preparer | Complex returns: self-employment, rental income, an estate |
Software choices and prices are compared in the best tax software in Canada guide, and the free options, including volunteer clinics and SimpleFile, are on the best free tax software page. How electronic and paper filing differ is covered in NETFILE vs paper filing, and when a professional is worth the fee in when to hire an accountant.
Step 2: Register for CRA My Account
My Account lets your software download your slips with Auto-fill my return, shows your RRSP and TFSA room, past returns and assessments, and lets you set up direct deposit for refunds. The CRA My Account guide covers registration and the main features.
Step 3: Enter your information
Start with personal information (name, address, date of birth, marital status), then enter your income slips. Marital status matters: the CRA treats a partner as common-law after 12 months of living together, among other tests, which am I common-law for tax purposes explains.
Step 4: Claim deductions and credits
Software prompts for the common items. Deductions (RRSP contributions, child care, moving expenses, union dues) reduce taxable income; credits (the basic personal amount, medical expenses, donations, tuition, the disability tax credit) reduce the tax itself. The deductions and credits guides list every claim, and how Canadian income tax works explains how they fit together.
Step 5: Review and submit
Check the return against your slips, then submit it electronically through NETFILE (you get a confirmation number right away) or mail a paper return. The common tax mistakes below list what to check before you submit, and the T1 General explainer walks through the key lines.
Step 6: Get your refund or pay your balance
A refund arrives by direct deposit or cheque after the CRA assesses the return; how long a tax refund takes has the processing times. A balance owing is due April 30 even if your filing deadline is later, and the ways to pay the CRA are listed separately.
Deadlines in brief
Most people file and pay by April 30. Self-employed people and their spouses or common-law partners have until June 15 to file, but any balance is still due April 30. The full calendar (RRSP deadline, slip deadlines, instalment dates, deadlines for a deceased person’s return) is on the tax deadlines page. Late-filing penalties are listed under common tax mistakes.
After you file
The CRA sends a Notice of Assessment confirming your refund or balance and your updated RRSP room. If you find an error later, fixing a mistake on a filed return explains the ways to change it. If you owe more than expected, why do I owe taxes this year goes through the usual causes.
Filing for the first time
Filing taxes for the first time is mostly the same as any other year, with a few differences: you have no previous return or Notice of Assessment to work from, CRA My Account has to be set up from scratch, and nothing carries forward yet. The steps above apply every year; if you are new to Canada, filing your first return as a newcomer covers arrival dates and world income.
Why Your First Return Matters
A first return starts your RRSP contribution room and puts you on the CRA’s records for income-tested benefits such as the Canada Child Benefit and the Canada Groceries and Essentials Benefit. Many student grants and loans also ask for a filed return.
Gather Your Documents
What You Will Need
| Document | What It Shows | Who Sends It |
|---|---|---|
| T4 slip | Employment income + tax withheld | Your employer (by end of February) |
| T4A slip | Other income (scholarships, freelance) | Payer |
| T5 slip | Interest and investment income | Your bank |
| T2202 | Tuition amounts | Your school |
| RRSP contribution receipt | RRSP contributions | Your financial institution |
| Social Insurance Number (SIN) | Your tax ID | Service Canada |
| Prior year return | Carry-forwards (if applicable) | Your records |
No T4 yet? Log into My CRA Account after late February: your employer’s submitted copies appear there.
First-Time Filer Checklist
- Gathered all T slips from employers, banks, schools
- Have your SIN ready
- Have your date of birth and address
- Collected receipts for any deductions (tuition, medical, moving, donations)
- Know which province you lived in on December 31 of the tax year
Set Up Your CRA My Account
CRA My Account is your personal online portal with the CRA. Registering before filing lets you:
- See your T slips directly
- Track your refund status
- Check RRSP and TFSA room
- Set up direct deposit for your refund
Register at canada.ca/my-cra-account. You will need your SIN, date of birth, and a code that the CRA mails to you. What you can do once you are in is covered in how to use CRA My Account.
Preparing and Submitting a First Return
Most tax software works as an interview: it asks about your personal details, each T slip and your deductions and credits, then fills in the T1 General return for you. The tax software guides compare the options, and the free tax software guide lists the no-cost ones.
The credits first-time filers most often claim are the basic personal amount, the tuition tax credit for post-secondary students and, with large medical bills, the medical expense tax credit.
Some first-ever returns can’t be verified electronically and have to go on paper. NETFILE vs paper filing sets out who must paper-file and how each method works.
Red flags before you submit: a very large refund (over $5,000) or a large balance owing usually points to an entry error, often in the T4 amounts.
Common First-Time Filer Mistakes
| Mistake | Consequence | How to Avoid |
|---|---|---|
| Not filing at all | Miss out on benefits | File every year, even with no income |
| Missing T slips | Audits or penalties | Log into CRA My Account to confirm all slips |
| Wrong province | Under/over paying tax | Use your address on December 31 of the tax year |
| Not claiming tuition | Unused tuition credits | Enter your T2202 amounts |
| Not setting up direct deposit | Wait weeks for cheque | Add bank info in software or CRA My Account |
After You File
The CRA’s reply is your first Notice of Assessment, which shows your assessed tax, your refund or balance owing, and your RRSP room for next year; how to read a Notice of Assessment walks through each section. Keep it on file, since you will need it next year.
Refunds on electronic returns with direct deposit usually arrive fastest; how long a tax refund takes has the timelines by method. Any balance owing is due on the payment date in the tax deadline calendar, and interest starts after it.
Key Tax Terms for First-Timers
| Term | Plain English |
|---|---|
| T4 | Slip from your employer showing income and tax withheld |
| NETFILE | System for electronically submitting your return to CRA |
| NOA | Notice of Assessment: CRA’s official response to your return |
| Refund | Money back because too much was withheld |
| Balance owing | Tax you still owe after credits and withholding |
| Tax credit | Reduces your tax bill |
| Tax deduction | Reduces your taxable income |
| Marginal tax rate | Tax rate on your last dollar of income |
| SIN | Social Insurance Number: your tax ID |
Common tax mistakes
Most costly tax mistakes happen before a return is submitted: a missing slip, an unclaimed credit, a wrong SIN, or a return filed after the deadline. If the return has already gone in, fixing a mistake on a filed return covers how to correct it.
Filing late when you owe triggers an automatic 5% penalty plus 1% per full month late, up to 12 months; the consequences of filing late page covers repeat-offence penalties and relief. The dates themselves are on the tax deadline calendar, and the guide to tax slips explains what each slip reports. After filing, how to know if your tax return was accepted and how to read your Notice of Assessment show whether CRA agreed with what you filed.
Top Tax Mistakes and How They’re Avoided
Filing Mistakes
| Mistake | Impact | How it’s avoided |
|---|---|---|
| Filing late (when you owe) | 5% penalty + 1%/month (up to 17%) | Filing by April 30 |
| Forgetting to file (no balance owing) | Lose refund; interrupts benefit payments (such as the Canada Child Benefit and the Canada Groceries and Essentials Benefit) | Filing even when nothing is owed |
| Wrong SIN or personal information | Delays processing; may not match CRA records | Checking the SIN on file with your employer and your marital status (common-law status counts) before submitting |
| Missing T-slips | CRA will reassess and may add penalties | Checking My Account for all slips by end of March (a forgotten T4 is the usual case) |
| Not reporting all income sources | CRA matches T-slips; penalties for omission | Reporting everything, including gig and side income |
| Using the wrong tax year’s software | Applies incorrect rates and credits | Using current-year certified software |
Missed Deductions and Credits
These are the claims most often left off a return. Each link goes to the page with the current amounts and rules.
| Commonly Missed Credit/Deduction | Who Qualifies | Rules and amounts |
|---|---|---|
| RRSP contributions | Anyone with contribution room | RRSP guide |
| Medical expenses | Prescribed costs above a threshold tied to net income; most over-the-counter medications do not qualify | Medical expense tax credit |
| Charitable donations | Anyone donating to registered charities | Donation credit calculator |
| Tuition credit (federal) | Post-secondary students | Tuition tax credit |
| Moving expenses | Moved 40+ km closer to work or school | Moving expense deduction |
| Home office deduction | Employees working from home or self-employed | Work-from-home deduction; employees need a T2200 from their employer |
| Child care expenses | Parents with children under 16 | Child care expense deduction |
| Disability tax credit | Individuals with qualifying impairment | Disability tax credit |
| Canada Workers Benefit (CWB) | Low-income workers | Canada Workers Benefit |
| Student loan interest | Anyone repaying government student loans | 14% credit on interest paid |
| Union/professional dues | Employees who pay union or professional fees | Union dues deduction |
| Northern residents deduction | Living in a prescribed northern zone | Northern residents deductions |
RRSP and TFSA Mistakes
| Mistake | Impact | How it’s avoided |
|---|---|---|
| Over-contributing to RRSP | 1%/month penalty on excess over $2,000 | Checking your limit on My Account before contributing (RRSP over-contribution rules) |
| Not claiming RRSP deduction for past contributions | Paying more tax than necessary | Carrying the deduction forward to a higher-income year |
| Contributing to RRSP after age 71 | Not allowed (must convert to RRIF by Dec 31 of year you turn 71) | A spousal RRSP accepts contributions until the end of the year your spouse turns 71 |
| Over-contributing to TFSA | 1%/month penalty on excess | Checking room on My Account; re-contributing a withdrawal in the same year can create an excess |
| Withdrawing from RRSP to fund short-term needs | Income tax + lost contribution room | A TFSA or emergency savings avoids both |
| Not naming a beneficiary | RRSP/TFSA goes through estate (probate + delays) | Naming a beneficiary on the account |
Self-Employment and Side Income Mistakes
| Mistake | Impact | How it’s avoided |
|---|---|---|
| Not reporting side income | CRA audits; penalties + interest | Reporting business income on Form T2125 |
| Not collecting GST/HST when required | Penalties; owe back GST/HST | Registering once revenue exceeds $30,000 in 4 rolling quarters (GST/HST on freelance income) |
| Not saving receipts for business expenses | Can’t claim deductions; lost savings | Keeping receipts digitally (photos/scans) for 6 years |
| Not making quarterly instalment payments | Interest charges | Paying quarterly tax instalments when net tax owing exceeds $3,000 |
| Claiming personal expenses as business | Audit risk; penalties | Claiming only expenses with a clear business purpose |
Penalties for Errors and Omissions
Paying late after filing on time brings no penalty, but unpaid balances accrue compound daily interest at the CRA’s overdue-tax prescribed rate (currently 7%). A false statement or omission made knowingly or through gross negligence carries a penalty of 50% of the understated tax or overstated credit, on top of the tax itself and interest.
The penalties for honest mistakes are significant but manageable; the penalties for fraud or gross negligence are far heavier. CRA treats corrections you make yourself far more leniently than corrections it discovers during a review or audit.
The Bottom Line
Most of these mistakes are caught by importing slips with CRA auto-fill, comparing claims with a spouse (see filing as a couple or separately), and reading the missed-deductions list above before submitting. Filing on time matters even when the balance can’t be paid yet, because the late-filing penalty is separate from and in addition to interest on amounts owing. For side income, GST/HST registration is required once revenue passes $30,000. Ways to lower the bill itself, rather than avoid errors, are in how to pay less tax.
Every filing guide
Getting started
- Your first tax return as a newcomer to Canada
- What a T1 General return is
- NETFILE vs paper filing
- Tax deadlines in Canada
- Accountant or DIY taxes
Who has to file
Paying less tax
- Ways to pay less tax in Canada
- Year-end tax planning checklist
- Pension income splitting
- Tax changes for next year
- What Budget 2026 changed for your finances
Refunds and balances owing
Fixing a filed return
Related pages
Browse All How to File Taxes in Canada: Steps, Filing Methods and Deadlines Articles
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Sources
The figures and rules on this page come from these sources, last checked against them on November 13, 2026. How we check facts.
- Canada Revenue Agency (2): Due dates and payment dates - Personal income taxInterest rates for the fourth calendar quarter