Call the Municipal Property Assessment Corporation (MPAC) at 1-866-296-6722 to appeal your property’s assessed value if you feel that it’s incorrect.


Use MPAC’s AboutMyProperty tool to access property details and compare your assessment to similar properties in the community.

Residential and farm property appeals

If your property is a farm or residential property, you must submit a Request for Reconsideration (RFR) to MPAC before filing a formal appeal with the Assessment Review Board (ARB).

Please note: You can only file an appeal with ARB if you don’t reach an agreement with the MPAC assessor.

Non-residential property appeals

If your property is industrial, commercial or multi-residential, you can:

Visit the ARB website for application forms and more information including appeal costs.

Supplementary or omitted tax bills

Under the Assessment Act and the Municipal Act, the Town of Milton must issue supplementary/omit tax bills when the Municipal Property Assessment Corporation (MPAC) has revalued a property because of new construction or improvements, resulting in an increase to the property's assessed value. MPAC will notify the property owner by a Property Assessment Change Notice to indicate the increase in assessment value.

If you believe your assessment is incorrect, refer to the Property Assessment Change Notice, for appeal deadlines and how to appeal.

Supplementary/omitted tax bills are issued throughout the year as the new assessments are received from MPAC and are due in one installment. Homeowners are encouraged to factor in these tax bills and set aside funds immediately following any major renovations to your property or the purchase of a newly built home. More information about how and when MPAC assesses newly built homes can be found on MPAC's website.

In the case where you built or purchased a brand new home or condominium, any tax bills received prior to the supplementary/omit tax billing are usually smaller and represent land only. If you receive a supplementary/omit tax bill and you did not own the home during all or a portion of the time indicated on the supplementary/omit tax bill, the bill should be forwarded to your lawyer to arrange for payment.

Please note: Supplementary/omitted tax bills do not include any outstanding or previously billed payments on your tax account.

There can also be more than one bill for multiple years delivered in one envelope. For example, if you’ve built a new home, you’ll get a supplementary tax bill based on the assessed value of the home from the date of occupancy or completion of alteration, which could be for more than one year.

How we calculate the tax amounts due

We calculate the tax amounts due and issue bills using the formula:

Assessment value X tax rate = tax amount due

For example: $350,000 X 0.757464% = $2,651.12 (365 Days)

MPAC can assess a property for the current year and up to two past years, retroactive to the closing date. 

Newly built homes

After you move into your new home, you will receive a Property Assessment Change Notice within three years. The Assessment Act allows MPAC to assess any new house that has been omitted from the Assessment Roll for the current and any part or all of the two previous years. Visit our property assessment page or Municipal Property Assessment Corporation (MPAC) for more information.

School support designation

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

There are 4 different school support designations to choose from:

  • English public
  • French public
  • English separate (Catholic)
  • French separate (Catholic)

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. Changing your school support online
Based on your eligibility, property owners and tenants registered with MPAC can view and update the school support designation online.

Please visit