7 Tax Mistakes Freelancers Make (And How to Avoid Them)

Tax season is stressful enough without discovering that a preventable mistake has cost you money — or worse, triggered a penalty. Here are seven of the most common and expensive tax mistakes made by freelancers and self-employed individuals, and exactly how to avoid each one.

Disclaimer: This article reflects general tax principles for Canadian (CRA) and US (IRS) self-employed filers. Tax laws change; consult a qualified tax professional before filing.

Mistake 1: Not Making Instalment Payments

Canada: If you owe more than $3,000 in federal income tax two years in a row, the CRA requires quarterly instalment payments: March 15, June 15, September 15, and December 15. Failing to pay on time results in instalment interest — calculated daily at the prescribed rate, which is typically several percentage points above prime.

United States: The IRS requires quarterly estimated tax payments if you expect to owe at least $1,000 in taxes for the year after withholding and credits. Due dates: April 15, June 15, September 15, January 15. The penalty for underpayment is calculated based on the federal short-term rate plus 3 percentage points.

Fix: Set aside 25–35% of every invoice payment into a separate account. Pay quarterly instalments on time.

Mistake 2: Not Tracking Mileage

Vehicle expenses are often the largest deduction available to self-employed people who drive for work. Without a contemporaneous mileage logbook, the deduction is not claimable — memory and estimates will not satisfy the CRA or IRS in an audit.

Fix: Enable GPS mileage tracking in TaxSort. It runs in the background and logs every trip automatically. Review and categorize trips as business or personal weekly.

Mistake 3: Mixing Personal and Business Finances

Using a single bank account or credit card for both personal and business expenses creates a bookkeeping nightmare and makes it easy to miss deductions — or accidentally claim personal expenses.

Fix: Open a dedicated business chequing account and use a business credit card for all work-related purchases. This creates a clean paper trail and makes expense review straightforward.

Mistake 4: Throwing Away Receipts

A bank or credit card statement shows that a transaction occurred but rarely shows what was purchased. Without the original receipt, many deductions cannot be substantiated.

Fix: Scan receipts immediately with TaxSort. Digital copies are accepted by both the CRA (IC78-10R5) and IRS (Rev. Proc. 98-25) as valid records.

Mistake 5: Missing the Home Office Deduction

Many freelancers working from home either don't know about this deduction or assume it is too complicated. For someone paying $1,800/month in rent and using a 10% home office, that is $2,160 per year in deductions they are missing.

Fix: Measure your workspace, keep your utility and rent receipts, and claim the workspace-in-the-home deduction on T2125 (Canada) or Form 8829 (US). See our full home office guide for the rules.

Mistake 6: Forgetting GST/HST Registration (Canada)

Many new freelancers and gig workers hit the $30,000 revenue threshold without realising they are legally required to register for and collect GST/HST. Failing to register results in penalties and interest on amounts that should have been collected and remitted.

Rideshare drivers have no threshold — they must register immediately (CRA technical interpretation).

Fix: Track your cumulative revenue throughout the year. Register via CRA My Business Account as soon as you reach $30,000. Once registered, add GST/HST to your invoices and set it aside — it is not your money.

Mistake 7: Filing Late

Canada: Self-employed individuals have until June 15 to file their T1 return, but any balance owing is still due April 30. A late-filing penalty of 5% of the balance owing applies, plus 1% per month for up to 12 months. If you're late a second time within three years, the penalty doubles.

United States: The filing deadline is April 15 (October 15 with an extension). The failure-to-file penalty is 5% of unpaid taxes per month, up to 25%. An extension to file is not an extension to pay — estimate and pay any owed tax by April 15.

Fix: File on time, even if you cannot pay in full. The failure-to-file penalty is far larger than the failure-to-pay penalty. If you cannot pay in full, the CRA and IRS both have payment arrangement options.