The Municipal Property Assessment Corporation (MPAC) is charged with the responsibility of assessing the value of all properties in Ontario.

Municipal Property Assessment Corporation

The Province of Ontario sets the policies as it relates to assessment and MPAC administers them. Assessed values are then provided to Municipalities, who then use these figures to determine your property taxes. Residential property taxes are calculated using assessed value, the City’s tax rate, the County of Lambton’s tax rate and an Education tax rate set by the Province of Ontario annually.

Additional information can be found on the MPAC website. In 2016, the Municipal Property Assessment Corporation (MPAC) updated the assessed value of every property in Ontario.

On August 16, 2023 the Ontario government filed Regulation 261/23 under the Assessment Act to extend the current assessment cycle, and the valuation date of January 1, 2016, through to the end of the 2024 taxation year. This means that property taxes for the 2024 taxation year will continue to be based on the January 1, 2016 valuation date. Property assessments will remain the same as they were for the 2023 tax year, unless there have been changes to the property. If you have any questions, please reach out to Municipal Property Assessment Corporation (MPAC).

Tax Year Request for Reconsideration Deadline

The Request for Reconsideration deadline for property owners who disagree with their property assessment is March 31 of the applicable tax year.

Do you have questions about your Property Assessment Notice?

Property owners with questions about their property assessment notice can visit the Understanding Your Assessment page on or contact the Municipal Property Assessment Corporation (MPAC) Customer Contact Centre at 1-866-296-MPAC (6722).

School Support Designation

Property owners in Ontario are required to support a school board, even if they do not have children or their children are not currently attending school. In the case of a residential property occupied by tenants, the tenants can direct the school support for that property. By default, school support is directed to your municipality’s English Public School Board.

The Municipal Property Assessment Corporation (MPAC) is legislatively required to collect school support information and provide it in the assessment roll to every municipality and school board. By ensuring that you are supporting the school board of your choosing, you will be able to vote in the next municipal and school board election for trustees in that school board. Property owners, occupants, and tenants can update their school support designation online at