It happens every year: the return goes in, the Notice of Assessment arrives, and then you find the receipt folder you forgot. The good news is that missed deductions aren't lost — the CRA has a formal process for claiming them after filing, and for most freelancers it takes about two weeks online.
1 First: Which Deductions Do Freelancers Actually Miss?
Before filing an adjustment for one forgotten receipt, sweep for the big ones. These are the deductions self-employed filers most commonly leave on the table:
- Home office expenses (T2125 line 9945) — rent or home costs prorated by workspace. Remember: it can't create a business loss, but unused amounts carry forward.
- Phone and internet (line 9220) — the business-use percentage is deductible even on a personal plan.
- Vehicle expenses (line 9281) — deductible in proportion to business kilometres, backed by a log.
- Capital cost allowance on computers, cameras, and equipment — big purchases aren't expensed in full; they're claimed over time through Area A (CCA). A missed laptop is a missed multi-year deduction.
- The deductible half of your CPP contributions — self-employed filers deduct the employer share (line 22200, via Schedule 8). Tax software does this automatically; hand-filers sometimes miss it.
- Meals with clients — deductible, but only to the 50% limit.
For the full sweep, run your bank statements through the free expense categorizer — it sorts every transaction onto the correct T2125 line — and skim 25 deductions most freelancers miss.
2 The Rules: When You Can Request a Change
- Wait for your Notice of Assessment. The CRA won't accept a change request until your original return has been assessed.
- One request at a time. If you've already submitted a change, wait for the CRA's response before requesting more.
- The 10-year limit. A refund cannot be issued for an adjustment requested more than 10 calendar years after the end of the tax year. Miss a 2016 deduction? The window is closing.
3 Three Ways to File the Adjustment
| Route | Where | Covers | Processing |
|---|---|---|---|
| Change my return | Your CRA account online | 2016 and later returns | ~2 weeks |
| ReFILE | Certified tax software | 2021 and later returns filed electronically | ~2 weeks |
| Form T1-ADJ | By mail to your tax centre | Anything online can't handle (within the 10-year window) | ~9 weeks |
Online is faster and walks you through the required fields. For mail, complete Form T1-ADJ and attach supporting documents for the entire revised amount — including amounts you already claimed but didn't previously send documents for.
4 What Happens Next
The CRA reviews the request and responds one of three ways: a Notice of Reassessment showing your changes were made (any refund is sent when processing completes), a reassessment with some changes plus an explanation of what wasn't accepted, or a letter explaining why no changes were made.
Heads-up on timing: adjustments to years beyond the CRA's normal 3-year reassessment period, or involving multiple returns, can take much longer than the standard 2 weeks — the CRA quotes up to 45 weeks for complex cases.
🔎 Find What You Missed First
Run last year's bank and credit card statements through the free Expense Categorizer. It sorts every transaction onto the correct T2125 line — so your adjustment request claims everything, once.
Sweep My Expenses — Free, No SignupMore Resources
- What to Do After Filing: the Full Checklist
- Every Tax Deduction for Canadian Freelancers (70+)
- 25 Deductions Most Freelancers Miss
- T2125 Line-by-Line Reference
- Self-Employed Tax Calculator
Adjustment rules and processing times on this page were verified against the CRA's "Changing a tax return" page (canada.ca, updated June 2026), checked July 11, 2026. Estimates only — general information, not tax advice.