What is it?
MPAC (the Municipal Property Assessment Corporation) sets the assessed value and the classification (residential, commercial and so on) of every property in Ontario, more than 5,000,000 of them. Your municipality multiplies that assessed value by the tax rate (the municipal rate plus the education rate) to get your property tax.
MPAC does not collect tax and does not set tax rates. The roles are split like this.
| Who | Does what |
|---|---|
| Ontario government | Writes the assessment and tax laws and sets the education tax rate |
| MPAC | Sets the assessed value and class of every property and mails the assessment notice |
| Municipality | Sets its tax rate to match its budget, mails the tax bill and collects the tax |
| Homeowner | Pays the tax; asks MPAC for a review if they disagree with the value |
What is on the Property Assessment Notice?
- Your assessed value and how much it changed since the last assessment
- Why you received the notice (province-wide update, new construction, ownership change, correction, and so on)
- Your roll number (a unique number for your property), address and description, municipality, classification (residential, for example) and school support (public or Catholic)
- A property summary: type, lot size, building area, year built and the key factors used in the assessment
- An access key for AboutMyProperty, MPAC’s online tool, where you can see how your home was assessed and compare it with similar homes nearby
- How to file a Request for Reconsideration if you disagree, and the deadline
The assessment notice is not a tax bill. The municipality sends the tax bill separately. Even in years without a province-wide update, MPAC mails an updated notice after changes such as new construction, an addition or a change of owner.
The valuation date is January 1, 2016, on a four-year cycle
The Assessment Act calls for a province-wide reassessment every four years, with each four-year period valued as of January 1 two years before the period starts. Taxes for 2017 to 2020 used January 1, 2016 values.
The next update (the 2020 update) was postponed because of COVID-19, and it is still postponed. York Region says the reassessment remains postponed until the results of a provincial review of the tax and assessment system are known. MPAC says 2026 property taxes are still based on January 1, 2016 values, so the value on your notice is close to a price from ten years ago.
For residential, farm, managed forest and some other property classes, when a reassessment raises a value, the increase is phased in over four years instead of all at once. The Act reduces the increase by 75% in the first year, 50% in the second and 25% in the third, and the Minister can set different rules by regulation. Check provincial announcements for when and how the next reassessment will happen.
Why is the assessed value different from market value?
First, because the valuation date is 2016. Second, because MPAC does not appraise homes one by one. It uses "mass appraisal": it gathers real sales in an area, builds a statistical model, and applies your home’s data (floor area, lot, year built and so on) to get a value.
So "sale price" and "current value" are different things. A sale price is what two people agreed on; current value is an opinion based on all the sales in the area. Paying a high price for a home does not change its assessed value to that price. Sales between family members, forced sales (for example, because of a mortgage foreclosure, a family break-up, or the government taking the land by expropriation) and sales from a builder are left out of the analysis.
Houses and condos are mostly valued by the "direct comparison approach", which compares your home with recent sales of similar homes.
If you disagree: Request for Reconsideration, then the Assessment Review Board
A Request for Reconsideration (RfR) asks MPAC to look again, and it is free. For residential, farm and managed forest property, the law says you must file an RfR before you can appeal to the Assessment Review Board (ARB). The ARB is an independent tribunal under the Ministry of the Attorney General, and it charges a filing fee.
The deadline is printed on your notice. By law it is normally March 31 of the tax year, and 120 days after the issuance date for the first year of a province-wide reassessment or for a supplementary or omitted assessment notice. MPAC usually answers within 180 days (up to 60 more if needed). If you still disagree, you have 90 days from the date MPAC issues the result to appeal to the ARB.
Step by step
- Ask yourself: "Could I have sold my home for this assessed value on January 1, 2016?" If yes, file the notice away and you are done.
- If not, log in to AboutMyProperty, check that MPAC’s data on your home is right (area, rooms, year built) and compare the assessed values of similar homes nearby.
- Gather evidence: photos showing data errors, sale prices and assessed values of comparable homes, an appraisal, and estimates for major repairs (cracked foundation, water damage and so on).
- File the RfR online through AboutMyProperty or by mail before the deadline. You get a confirmation, and the result normally comes in writing within 180 days.
- If MPAC agrees to a change, it sends a new notice and Minutes of Settlement and tells the municipality so your tax can be adjusted.
- If you still disagree, appeal to the ARB within 90 days of the result (a fee applies). Residential appeals use the summary proceeding and are usually heard by teleconference.
How to use it when you buy
- You can find a listing’s assessed value on the listing or on the seller’s tax bill. Assessed value times the combined municipal and education tax rate is roughly the yearly property tax (see "Property tax").
- A low assessed value does not make a home a bargain, and a high one does not make it a better home. It is a 2016-based statistical figure. Judge value with an appraisal or a comparative market analysis instead.
- For new construction, MPAC mails an updated notice after the change, and the city may then send a separate tax bill (see "Property tax"). Ask the city’s tax office how your first-year tax will be billed.
- When the owner changes, MPAC mails an updated notice. Check the data on it as soon as it arrives and report anything wrong.
Example
In February 2026 you receive a notice showing $820,000 for your North York townhouse. Similar units in the complex sold for around $700,000 in early 2016, and the notice lists a larger finished-basement area than you actually have.
On AboutMyProperty you see that neighbouring units are assessed at $690,000 to $730,000. You attach photos and comparables and file an RfR before March 31. In July MPAC corrects the data and sends a new notice at $715,000, and the city recalculates that year’s tax. Had you disagreed with the result, you could have appealed to the ARB within 90 days of the result date. (The figures are made up to illustrate.)
What the law and official sources say
Quotes are copied word for word. The "In plain words" lines are our explanation, not an official translation.
4. For the period consisting of the four taxation years from 2017 to 2020, land is valued as of January 1, 2016. 5. After 2020, for each subsequent period consisting of four consecutive taxation years, land is valued as of January 1 of the year that precedes the period by two years.In plain wordsTaxes for 2017 to 2020 use January 1, 2016 values, and each later four-year period uses January 1 two years before it starts. The Minister can set a different date (subsection 5), and in practice the reassessment has been postponed, so 2016 still applies.
Source: ontario.ca/laws/statute/90a31 · checked Oct 30, 2026
Property assessments for the 2026 property tax year will continue to be based on January 1, 2016 current values.In plain wordsThe assessed values used for 2026 property tax are still January 1, 2016 values.
Source: mpac.ca/en/UnderstandingYourAssessment/ReadingYourPropertyAssessmentNotice · checked Oct 30, 2026
If the current value of land increases because of a general reassessment, the current value of the land shall be reduced according to the following rules: 1. For the first taxation year to which the general reassessment applies, the current value of the land is reduced by an amount equal to 75 per cent of the eligible increase. 2. For the taxation year following the taxation year in paragraph 1, the current value of the land is reduced by an amount equal to 50 per cent of the eligible increase. 3. For the taxation year following the taxation year in paragraph 2, the current value of the land is reduced by an amount equal to 25 per cent of the eligible increase.In plain wordsWhen a reassessment raises a residential value, only 25% of the increase counts in year one, 50% in year two, 75% in year three and the full amount (100%) in year four.
Source: ontario.ca/laws/statute/90a31 · checked Oct 30, 2026
A request for reconsideration under subsection (1) must be made no later than March 31 of the taxation year in respect of which the request is made. … Despite subsection (1.1), for any year that is the first taxation year to which a general reassessment applies, a request for reconsideration in respect of the taxation year must be made no later than 120 days after the issuance date on the notice of assessment.In plain wordsAn RfR is normally due by March 31 of the tax year. In the first year of a province-wide reassessment, the deadline is 120 days after the issuance date on the notice.
Source: ontario.ca/laws/statute/90a31 · checked Oct 30, 2026
If a property is in the residential, farm or managed forests property class, or in such other circumstances as the Minister may prescribe, no appeal may be brought to the Assessment Review Board under subsection (1) by a person who is entitled to make a request for reconsideration under section 39.1 in respect of the property, if the person has not made the request within the time required under that section.In plain wordsFor residential, farm and managed forest property, you cannot appeal to the Assessment Review Board unless you filed an RfR on time first.
Source: ontario.ca/laws/statute/90a31 · checked Oct 30, 2026
You have 90 days from the date that we issue the results of your Request for Reconsideration to submit an appeal to the Assessment Review Board.In plain wordsYou must appeal to the Assessment Review Board within 90 days of the date MPAC issues your RfR result.
Source: mpac.ca/en/MakingChangesUpdates/DisagreeingYourAssessedValue/RfR · checked Oct 30, 2026
The sale price of a property is the final dollar figure negotiated and agreed on between parties. A property’s current value is an informed opinion of its worth, based on analysis of all sales transactions in a given market area.In plain wordsA sale price is what two parties agreed on; the assessed (current) value is an opinion drawn from all sales in the area. They are not the same.
Source: mpac.ca/en/UnderstandingYourAssessment/HowSalesAffectYourPropertyAssessment · checked Oct 30, 2026
Common questions
Does MPAC collect property tax?
No. MPAC only sets the assessed value. The municipality sets the rate, mails the bill and collects the money. Ask the city’s tax office about amounts and payments, and MPAC about the assessed value.
Will my purchase price become my assessed value?
Not directly. MPAC analyzes all sales in the area statistically to find the value on the valuation date (January 1, 2016). One sale does not become the assessment, and sales from a builder or between family members are left out of the analysis.
Does a Request for Reconsideration cost anything?
No, it is free. An appeal to the Assessment Review Board has a fee, and for residential property you must file an RfR before you can go to the ARB.
What if I missed the deadline?
You usually lose the review for that year. The Act lets the ARB extend the deadline during the tax year if there are extenuating circumstances, but that is not guaranteed. Watch the deadline on next year’s notice.
If my assessed value goes down, does my tax always go down?
If only your home is lowered through an RfR, your tax for that year goes down. In a province-wide reassessment all values move together, so what matters is whether yours rose less than average. And if the city’s budget grows, the rate rises and your tax can go up even with the same assessed value.
Guides that use this term
Sources checked
- Assessment Act, R.S.O. 1990, c. A.31 (e-Laws) · checked Oct 30, 2026
- MPAC, Reading Your Property Assessment Notice · checked Oct 30, 2026
- MPAC, How to file a Request for Reconsideration (RfR) · checked Oct 30, 2026
- MPAC, How to file an appeal · checked Oct 30, 2026
- MPAC, How Sales Affect Your Property Assessment · checked Oct 30, 2026
- MPAC, Three Approaches to Value · checked Oct 30, 2026
- MPAC, How will my property assessment impact my property taxes? · checked Oct 30, 2026
- Ontario.ca, Property tax (valuation date) · checked Oct 30, 2026
- York Region, York Region Property Tax (reassessment postponed) · checked Oct 30, 2026