Property Assessment and Taxation FAQ


Municipal Office

395 Mulock Drive P.O. Box 328 Station Main, Newmarket, Ontario
L3Y 4X7

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What is the Municipal Property Assessment Corporation (MPAC)?

The Municipal Property Assessment Corporation (MPAC) is an independent, not-for-profit corporation funded by all Ontario municipalities. MPAC's role is to assess the value of properties according to the Assessment Act and other Ontario government regulations.

What is the 2016 Assessment Update

Every four years, MPAC updates the value of every property in the province as part of Ontario's assessment cycle. This year, MPAC will update the assessed values of more than five million properties. The current Assessment Update is took place in 2016, based on a valuation date of January 1, 2016. These assessments were applicable to the 2017 to 2023 property tax years. 

What is happening this year?

Due to the COVID-19 pandemic, the Ontario government has postponed the 2020 Assessment Update. On August 16, 2023, the Ontario government filed a regulation to amend the Assessment Act, extending the postponement of a province-wide reassessment through the end of the 2021-2024 assessment cycle.

What is a valuation date?

To stay consistent, MPAC values each property based on a legislated valuation date. A valuation date is what a property could have reasonably sold for if bought by a willing buyer from a willing seller, as of January 1, 2016.

How are the 2016 values being determined?

To establish a property's assessed value, MPAC analyzes sales of comparable properties in the property owner's area and all the key features that affect market value. This method, called Current Value Assessment, is used by most assessment jurisdictions in North America.

For residential properties, there are five major factors that generally account for 85% of a property's value:

  • Location
  • Lot dimensions
  • Living area
  • Age of the property (adjusted for any major renovations or additions)
  • Quality of construction 

Values for the 2016 Assessment Update are based on market analysis, data collection and preparation and property level reviews.

When will property owners receive their property assessment notice?

Residential property owners across Ontario will receive their new assessment Notices over a 21-week period, starting on April 4, 2016. The residential Notice mailing date for all of York Region – which includes the Town of Newmarket – is Monday, June 13, 2016. Non-residential property owners will receive their new assessments starting on October 11, 2016.

What is the relationship between assessment and taxation?

MPAC's property assessments provide the foundation on which municipalities – including the Town of Newmarket – base property taxes. Here is how it works: 

  1. Each municipality determines how much it costs to provide all the services in a community – such as waste management, parks, fire protection, roads, sidewalks and public transit.
  2. Once that's done, the municipality takes all of the property values and determines tax rates for different property types to make sure there is enough money to provide these services.
  3. This tax rate is then used to calculate how much property tax residents will pay to their municipality.
  4. In addition to the local municipal tax rate, the Regional Municipality of York sets their tax rates, and the Province of Ontario sets the education tax rate.  

If a property owner's assessment increases, will they have to pay more property tax?

Not necessarily. If the assessed value of a home has increased more than the average for the municipality, property owners may pay proportionately more in property taxes. If it has increased in value less than the average, property owners may pay proportionately less in property taxes. This is prior to any budgetary changes that may occur. 

Under the Assessment Act, assessment increases are introduced gradually over four years, for all property types. As such, market increases in assessed value between the January 1, 2012 and January 1, 2016 legislated valuation dates will be introduced evenly over four years (2017 to 2020). The phased-in values are indicated on Property Assessment Notice. The phase-in program does not apply to decreases in assessed value, which are introduced immediately.

What if a property owner hasn't received their Notice?

The first step is to check the Notice mailing schedule. Residential Notices are being mailed over a 21-week period starting April 4. Property owners should contact MPAC's Customer Contact Centre at 1-866-296-MPAC (6722), or 1-877-889-MPAC (6722) if they haven't received their Property Assessment Notice by the anticipated date.

How can property owners check the accuracy of their assessment?

Property owners should review their Notice, and ask themselves if they could have sold their property for the assessed value as of January 1, 2016. Next, they should visit to learn how and why their property was assessed the way it was, and to compare their assessment with others in their neighbourhood. 

If property owners have questions, they can call MPAC's Customer Contact Centre at 1-866-296-MPAC (6722), or 1-877-889-MPAC (6722), or visit a local MPAC office.

 What is AboutMyProperty™?

AboutMyProperty™ is a secure, online, easy-to-use, self-serve website that allows property owners to learn more about how their property was assessed, see the information MPAC has on file as well as compare it to others in their neighbourhood or area. Information on property values and market trends are also available through the site – free of charge.

What if property owners don't agree with their assessment?

If property owners disagree with MPAC's assessment or classification of their property, they can file a Request for Reconsideration and MPAC will review their assessment, free of charge. The deadline to file this request is included on each property owner's Notice. There are two ways to file a request: ​

  1. At, property owners will be able to attach documents, pictures and reports to accompany their request, as well as check its status.

  2. They may also mail or fax their form to MPAC. Forms are available at​