A tax return can look simple. But some mistakes can cost you money.
Here are 7 common mistakes to avoid.
1. Confusing the filing deadline and the payment deadline
The filing date and the payment date are not always the same.
| Situation | Filing deadline | Payment deadline |
|---|---|---|
| Employee | April 30, 2026 | April 30, 2026 |
| Self-employed worker | June 15, 2026 (under certain conditions) | April 30, 2026 |
How to fix it
Estimate your balance and pay before April 30.
2. Forgetting a source of income
Some income is easy to forget:
- forgotten slip
- bank interest
- self-employment income
- rental income
- income from a digital platform
How to fix it
Check all your documents before filing.
3. Mixing personal and business expenses
Some expenses are often mixed:
- phone
- meals
- computer
- vehicle
- home office
How to fix it
Keep business expenses separate from personal expenses.
4. Claiming an expense without keeping the proof
You must keep proof for every expense claimed:
- receipts
- invoices
- contracts
- statements
How to fix it
Store your documents in one place all year.
5. Forgetting important credits and deductions
Some amounts can reduce your tax:
- RRSP contributions
- medical expenses
- childcare expenses
- tuition fees
- donations
How to fix it
Review the credits and deductions that apply to you.
6. Calculating home office or vehicle use incorrectly
A wrong calculation can increase the risk of an error.
This is common with home office expenses and vehicle use.
How to fix it
Use a clear and reasonable calculation. Keep the details.
7. Sending the return without reviewing it
Before sending, check:
- personal information
- income
- deductions
- banking details
How to fix it
Read your return before sending it. Then read your notice of assessment.
Good preparation helps a lot.
CH Solutions can help you prepare and file your tax return.
This article gives general information only. Each situation is different.