Introduction to Property Assessment


In Ontario, property assessments are based on the current value as of a specific date. The Assessment Act determines the date of valuation for each taxation year. These dates are shown below.

The Ontario assessment system is made up of four key organizations that each have a role in the assessment process.

Assessment Review Board (ARB)

The ARB hears appeals on your assessment. If you think your assessment is incorrect you can file an appeal with the ARB. For information on how to appeal, see the section on filing an appeal.

Municipal Property Assessment Corporation (MPAC)

MPAC is the organization that prepares and sends out property assessments. The ARB and MPAC are two separate organizations. For questions about your assessment, contact MPAC.


Municipalities set tax rates. They also issue your property tax bill. Contact your municipality if you have questions about your property taxes.

Ministry of Finance

The Ontario government, through the Ministry, is responsible for setting the law, including the Assessment Act and related regulations.

Legislation and Rules

See the above link for a listing of the legislation, regulations and Rules that are related to the ARB.