How is my property tax assessment determined in Ontario?
Property taxes in Ontario are levied by municipalities based on the assessed value of your property as determined by the Municipal Property Assessment Corporation (MPAC), a provincial agency. MPAC assesses all properties in Ontario and assigns a "current value assessment" (CVA) that is intended to reflect the property's estimated market value as of a specific valuation date.
Property assessments in Ontario are conducted on a four-year cycle. Within each cycle, your assessed value is gradually "phased in" over the four years rather than jumping immediately to the new value — this phasing-in mechanism is designed to smooth out large one-year tax increases. The municipal tax rate (the "mill rate") is then set annually by each municipality based on its budget requirements and applied to your assessed value to calculate your annual property tax bill.
If you believe your assessment is incorrect, you can file a Request for Reconsideration with MPAC within the prescribed deadline. If MPAC does not resolve the dispute to your satisfaction, you can appeal to the Assessment Review Board, an independent adjudicative tribunal. Commercial property owners and residential property owners both have the right to appeal, but the process, timelines, and evidence requirements differ.
Key takeaways
- MPAC sets property assessments in Ontario on a four-year cycle using estimated market value.
- Assessments are phased in over four years to reduce sharp annual tax increases.
- Municipalities set the tax rate annually — your bill depends on both the assessment and the rate.
- Incorrect assessments can be challenged by filing with MPAC and, if needed, the Assessment Review Board.