Forgot an expense after filing your taxes?

Finding a receipt after filing does not necessarily mean the opportunity is lost. Start by checking what was already claimed and whether the expense qualifies. A review can help establish whether a change to your personal tax return is appropriate.

Arsen Accounting Services · CRA sources checked October 24, 2026. This guide concerns personal T1 returns, including self-employed reporting.

Start with the return you filed

Gather the filed return and its supporting schedules, along with your notice of assessment. The amount may already be included in an expense total. If a preparer helped you, identify the item you are concerned about so it can be checked against the records used.

CRA requires you to receive your notice of assessment before requesting a change. If you have already requested an adjustment, wait for CRA’s response before asking for further changes to that return. See CRA’s guidance on changing a tax return.

Gather a small review file

• The tax year, filed return, assessment and any relevant CRA correspondence.
• The receipt or invoice, purchase date, amount and description of the expense.
• A short explanation of how it relates to your work, rental activity or other proposed claim.
• Details of personal use, reimbursements or amounts that might already have been included elsewhere.

Keep the supporting records available. For business purchases, CRA’s record-keeping guidance explains the information receipts and other documents should contain.

Check eligibility before assuming a refund

For self-employed work, personal spending cannot simply be added to business expenses. Mixed-use costs need the business portion identified, and equipment purchases can have different treatment from day-to-day expenses. The relevant year and the kind of cost matter. Review CRA’s business-expense guidance.

A newly found receipt does not guarantee a deduction or refund. The review should establish the facts and any appropriate correction before a request is submitted.

Ask about a review and its scope

In your first inquiry, mention the tax year, the type of expense and whether you have received your assessment. Arsen Accounting is based in Ontario and provides remote Canadian tax preparation. We can discuss a review of a previously filed T1 and confirm the work and fee before starting.

See T1 adjustment pricing and conditions. Keep SINs, account numbers and tax documents for the sharing arrangements agreed after your initial inquiry.

Ask about a missed-expense review →

Prepare for your next return

Keep records by tax year and activity, and flag costs you are unsure how to classify. Our self-employed document checklist and self-employed tax preparation page provide starting points.

General preparation guidance. Eligibility and the appropriate adjustment process depend on your circumstances and tax year.