The 5 Most Common Tax Filing Mistakes in Canada and How to Avoid Them
- Thais Nardi
- Dec 8, 2024
- 2 min read

Tax season can feel overwhelming, especially if you’re unsure about the process. But the good news is that many of the most common tax filing mistakes can be avoided with a little preparation and the right guidance.
In this article, we’ll explore five mistakes that Canadians often make when filing their taxes—and how you can steer clear of them to maximize your return and stay stress-free.
1. Missing Important Deadlines
One of the most frequent errors is waiting too long to file taxes. In Canada, the deadline for most individuals is April 30 of the following year. Missing this date can lead to penalties, interest charges, and unnecessary stress.
How to Avoid It:
Mark important dates on your calendar now.
Gather your documents early.
Work with a professional to ensure your return is filed on time.
2. Forgetting to Report All Income
Whether it’s from a side hustle, rental property, or investments, all sources of income must be reported. Forgetting even small amounts can lead to issues with the CRA (Canada Revenue Agency).
How to Avoid It:
Keep track of all income throughout the year.
Save all T4, T4A, and other relevant income slips.
Consult with an accountant to make sure nothing is overlooked.
3. Overlooking Deductions and Credits
Canada offers a variety of deductions and tax credits, like the Climate Action Incentive and tuition credits. Many taxpayers miss out simply because they’re unaware of what they qualify for.
How to Avoid It:
Research the deductions and credits available for your situation.
Use tools like My CRA Account to stay informed.
A tax expert can help you identify what you’re eligible for.

4. Making Math Errors or Typos
Simple mistakes, like incorrect numbers or forgetting to sign your return, can delay your refund or even trigger an audit.
How to Avoid It:
Double-check your work before submitting.
Consider using tax software or hiring a professional.
5. Not Planning Ahead for Self-Employment or Business Income
Freelancers, contractors, and business owners face unique tax challenges, like tracking expenses and paying GST/HST. Without proper planning, it’s easy to miss deductions or fall behind on payments.
How to Avoid It:
Keep organized records of income and expenses.
Set aside money for taxes throughout the year.
Work with a bookkeeper or accountant to stay on top of your finances.
Make Tax Season Easy
Avoiding these common mistakes doesn’t have to be difficult. By staying organized and seeking the right support, you can file your taxes confidently and even maximize your refund.
At Nardi Accounting, we specialize in helping individuals and small businesses navigate their taxes with ease. Let us handle the complexities so you can focus on what matters most.
Ready to get started? Contact us today!
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