Running a small business? Awesome. Managing your taxes? Less awesome.
I get it—between growing your business, keeping clients happy, and juggling a million other things, taxes aren’t exactly top of mind. But here’s the thing: business tax mistakes can cost you big time. And trust me, I’ve seen the same common tax mistakes for small businesses over and over again.
So, let’s go over the biggest tax pitfalls small business owners run into—and how you can avoid them like a pro.
1. Treating Bookkeeping Like an Afterthought
Look, I know bookkeeping isn’t the most exciting part of running a business. But if you’re not keeping track of income and expenses properly, you’re making tax time way harder than it needs to be. Worse? If the CRA comes knocking and your records are a mess, you could lose out on deductions—or even face penalties.
What to do instead: Get on top of your books now, not in April. Use tools like QuickBooks or Wave, and make sure you keep receipts, invoices, and bank statements organized.
2. Mixing Business and Personal Finances
If you’re paying for business expenses with your personal credit card—or using your business account for personal spending—stop now. Seriously. Not only does this make tax filing a nightmare, but if the CRA ever audits you, they’ll have questions. Lots of them.
What to do instead: Open a dedicated business bank account and credit card. This keeps everything clean, clear, and way easier to track.
3. Leaving Tax Deductions on the Table
You might be paying way more in taxes than you need to—just because you’re not claiming all the deductions you’re entitled to. I see business owners missing out on things like:
- Mileage (if you use your car for business)
- Home office expenses (if you work from home)
- Meals and entertainment (within CRA limits, of course)
- Professional development (courses, conferences, memberships)
What to do instead: Keep detailed records and chat with your CPA about every possible deduction you qualify for. Avoiding business tax mistakes like this can save you a lot at year-end.
4. Forgetting About Sales Tax (HST/GST)
This one’s a big one. If your revenue hits $30,000 in a 12-month period, you’re legally required to register for HST/GST. Miss it, and not only will you owe the CRA back taxes, but you might get slapped with penalties, too.
What to do instead: Track your revenue and register before you hit the $30,000 mark. And once you’re registered? Set reminders to remit your sales tax on time—because late fees hurt.
5. Not Setting Money Aside for Taxes
Ever get to tax season and realize you don’t have enough cash to pay your tax bill? Yeah, that’s not fun. But it happens all the time because business owners forget that not all the money they make is theirs to spend.
What to do instead: Every time you get paid, move 25-30% into a separate savings account for taxes. Future you will thank you. This simple habit can help you avoid one of the most common tax mistakes for small businesses—being caught off guard by a big tax bill.
6. Ignoring Quarterly Tax Installments
If you owe more than $3,000 in taxes at the end of the year, the CRA expects you to start paying in quarterly installments. Ignore them, and you’ll be hit with interest charges.
What to do instead: Check if you need to make installments, and if you do, set up automatic transfers so you don’t miss a deadline.
7. Waiting Until the Last Minute to File
Scrambling to pull everything together at the last minute leads to missed deductions, calculation errors, and—if you miss the deadline—late penalties.
What to do instead: Stay on top of your books all year, and don’t wait until tax season to talk to your CPA.
Final Thoughts: Your CPA is Your Best Friend (at Least for Taxes!)
Taxes don’t have to be painful. When you stay organized, plan ahead, and actually use the resources available to you (hi, that’s me!), you can save money, avoid stress, and keep your business running smoothly.
Got questions? Need a solid tax plan? Let’s chat—I’d love to help you keep more of your hard-earned money.
Contact Swain CPA today!
FAQ
1. What’s the most common tax mistake small businesses make?
One of the biggest mistakes? Not setting money aside for taxes. It’s easy to focus on running your business and forget that a chunk of your earnings actually belongs to the CRA. Then tax time rolls around, and suddenly, you’re scrambling to find cash to cover your bill.
To avoid this, get into the habit of setting aside 25-30% of your income for taxes. A separate savings account works great for this. If you’re not sure how much you’ll owe, work with a CPA to estimate it—trust me, your future self will thank you.
2. What happens if I don’t file my business taxes on time?
Miss the deadline, and the CRA starts charging penalties immediately. The late-filing penalty is 5% of what you owe, plus 1% for every month you’re late (up to 12 months). If you’re late multiple years in a row, those penalties double.
Even if you can’t pay your full tax bill, file your return on time. The CRA is more lenient with payment plans than they are with missing filings. And if you think you’ll miss the deadline, talk to your CPA early—we can help you avoid extra costs.
3. Can I claim business expenses if I don’t keep receipts?
No receipts? No deduction. Simple as that.
One of the biggest business tax mistakes I see is business owners trying to claim expenses without proper documentation. If the CRA audits you and you can’t back up your claims, those deductions will be denied—and you’ll owe more tax (plus potential penalties).
The fix? Keep every business-related receipt, invoice, and bank statement. If you’re worried about losing paper copies, use an app like Dext, Hubdoc, or QuickBooks to store digital versions.
4. How can I avoid getting audited by the CRA?
There’s no surefire way to guarantee you won’t be audited, but some business tax mistakes make you a bigger target. The CRA looks for red flags like:
- Large, unusual deductions (especially meals, travel, and home office expenses)
- Reporting a loss multiple years in a row
- Not reporting all your income (cash transactions included)
- Mixing business and personal expenses
The best way to stay off the CRA’s radar? Keep clean, accurate records, claim only legitimate expenses, and file everything correctly and on time. And if you do get audited? Having solid bookkeeping makes the process way less stressful.
5. I made a mistake on my tax return—what should I do?
If you realize you made a mistake after filing, don’t ignore it. The CRA allows you to correct errors by filing an adjustment request (T1-ADJ for sole proprietors, or a T2 amendment for corporations).If the mistake means you owe more tax, fix it ASAP—interest starts adding up right away. If you overpaid, you might even get some money back. Either way, catching errors early helps you avoid penalties and keeps your business in good standing.
