Disputing Your Property Assessment: MPAC and the Assessment Review Board

Ontario property taxes are based on the assessed value set by the Municipal Property Assessment Corporation (MPAC).

Step 1: Check your assessment

• Look at your notice and your property details on MPAC's AboutMyProperty website.
• Check facts such as size, lot area, bedrooms and features.
• Compare with similar nearby properties.

Step 2: Request for Reconsideration

• Free, and required for most residential properties before an appeal.
• Deadline: usually March 31 of the tax year, or 120 days after the notice date if that is later.
• Explain why the value is wrong, with evidence.

Step 3: Assessment Review Board

• If you disagree with MPAC's RfR decision, appeal to the Assessment Review Board (ARB) within 90 days.
• There is a filing fee.
• The ARB can hold mediation and a hearing.

Good evidence

• Recent sales of similar homes
• Photos of condition problems
• An appraisal, in some cases

Note

Ontario's assessments have been based on 2016 values for several years; check MPAC for the current valuation date.

Sources

• MPAC: Request for Reconsideration
• Assessment Review Board (Tribunals Ontario)
• Assessment Act (Ontario)

Read next: The Condominium Authority Tribunal: What It Can Decide

General Ontario legal information, not legal advice for your matter, and reading it does not create a retainer. Sources checked 16 October 2026: check the current law, forms and dates before you act.

Photos from Unsplash: gray click pen on black book · a law office sign on the side of a building.

This article is general information for people in Ontario, not legal advice. Rules, forms and deadlines change, and every situation is different. Check the current rule or speak to a licensed legal professional before you act.