Property Assessment FAQs

​Who determines the assessed value of a property?

The Municipal Property Assessment Corporation (MPAC) was established by the Ontario Property Assessment Corporation Act. MPAC started operating on December 31, 1998, when the Government of Ontario transferred responsibility for property assessment to the Corporation.

What does MPAC do?

MPAC administers a uniform, province-wide system based on current value assessment. It provides municipalities with a range of services, including the preparation of an annual assessment roll for use by a municipality in calculating property taxes. MPAC carries out its activities in accordance with the provisions of the Assessment Act, as well as regulations issued under the Act by the Province of Ontario.

How does MPAC establish the assessed value of my property?

The real estate market determines the value of properties. MPAC analyzes market information from similar types of property in your area to establish your property's value. Any one of three methods may be used for this analysis: the selling price of a property (residential), the rental income a property generates (office building), or the cost to replace a property (industrial). Each method takes into consideration the location of a property, the size and quality of any buildings, and features that might add to or take away from a property's value.

What will my assessed value be used for?

The assessed value of a property will be used by the municipality to calculate the amount of the property taxes.

How are residential property taxes calculated?

Residential property taxes are calculated using your assessed value, the municipal tax rate, and an education tax rate, which is set by the Province of Ontario.

The formula is:

Assessed Value x Municipal Tax Rate = Amount of Municipal Property Tax

Assessed Value x Education Tax Rate = Amount of Education Property Tax

Municipal Property Tax + Education Property Tax = Your Property Taxes

If my assessed value changes, will my taxes change?

It depends in part on whether your assessed value goes up or down more than the values of similar properties in your community. The assessed value is only one part of the process of setting property taxes. A lot depends on the revenue requirements of the municipality, as well as the amount required by the Province to fund education. As well, Provincial legislation affecting municipal taxation may be amended, which could affect municipal tax rates. Only by applying the current tax rates to your property can you tell if a change in your assessed value will result in a change in your property taxes.

How do I change my school support?

Property owners and tenants who are registered with MPAC can change their school support designation by logging into the MPAC's AboutMyProperty online portal. There is also a Guide: MPAC's Online Portal to Direct School Support available to assist users with how to navigate changing their school support designation online. 

Alternatively you can submit a paper application by using the Alternative method - changing your school support or by calling customer support at 1-866-296-6722.

Why has my assessed value changed?

The values of all properties in Ontario have been updated from a previous valuation date to a new valuation date. Changes in assessed values reflect any increases or decreases in the values of properties in your municipality.  For the 2009 year and beyond, increases in the values of properties are phased-in over a four-year period.

How can I find out the assessed value of properties similar to mine?

MPAC offers the AboutMyProperty service on their website to learn how your property was assessed and compare your property to others in your neighbourhood. It is very user-friendly and quite simple. Search properties by roll number or street address.

Shouldn't my assessed value be the same as the purchase price?

The sale of real property is affected by many factors, such as a buyer's desire to acquire a particular property and a seller's willingness to reduce the sale price in order to achieve a sale. This could result in similar properties selling for different amounts, which would result in different taxes. MPAC determines an assessed value that is in the middle range of selling prices for similar properties. This ensures that the tax burden is equitably shared among similar properties.

Another reason the assessed value and price might not be the same is that the market may have changed between the valuation date and the date you purchased your property.

What if I don't think my assessed value is correct?

You can ask MPAC to review your assessed value through a process called Request for Reconsideration. If the reconsideration process results in a change to your assessment, it will be made. If not, you can file a complaint to an independent tribunal called the Assessment Review Board. Both yourself and MPAC will be asked to appear before the Board at a hearing to present evidence. The Board's decision would be binding for both you and MPAC and, if it reduces your assessed value, your taxes would be adjusted by the Municipality of Chatham-Kent. The Municipality of Chatham-Kent also has the right to appear at your hearing before the Board.

Who do I contact if I have questions?

If you have questions about your Property Assessment Notice, assessed value, or about assessment in general, contact the MPAC office at 1-866-296-6722 or visit their MPAC website. If you have questions about your municipal property taxes or municipal tax rates, contact the Chatham-Kent Tax Office at 519-360-1998 or email