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A property assessment is the value a public agency puts on your home for tax purposes, and in Ontario that value is tied to a date in 2016, not to today’s market. So it’s a poor guide to what your house would sell for. It’s still the number your property tax bill is built on.
What does a property assessment actually measure?
In Ontario the Municipal Property Assessment Corporation (MPAC) values every property. Its notice shows the assessed value and the property class as of a legislated valuation date. For 2026 that date is still 1 January 2016, because the province postponed the reassessment that was due in 2020.
Property assessments for the 2026 property tax year will continue to be based on January 1, 2016 current values.
Reading Your Property Assessment Notice, mpac.ca
That means the figure on your notice is roughly what the property would have sold for on that January day, in its present condition. A house that sold last month at a much higher price can still carry the old number. Don’t treat it as an appraisal, and don’t quote it to a buyer.
Other provinces run their own systems and dates, and we haven’t checked them here, so read your own assessor’s notice if you live elsewhere.
Who sets what on your tax bill?
| Who | What they decide |
|---|---|
| MPAC | Assessed value and property class |
| Your municipality | Tax rates, based on the money it needs to raise, and the bill itself |
| Ontario government | The legal framework and the education tax rates |
Your tax is the assessed value multiplied by the combined municipal and education rate for your property class. MPAC doesn’t set the rate and doesn’t collect a cent.
If my assessment goes up, does my tax go up?
Not automatically. MPAC says what matters is how your change compares with the average for your property class in your municipality. Rise less than the average and your tax will likely fall. Rise more and it will likely climb.
Take a home assessed at $500,000 with a combined rate of 0.75%. The property tax calculator gives $3,750 a year. Say the assessment climbs to $550,000 and the rate stays put: the bill becomes $4,125. But if the council trims the rate to 0.68% to offset a citywide rise, the same $550,000 gives $3,740. A higher assessment, a slightly lower bill.
We used round made-up rates for this example. Your real rate is on your tax bill, and it includes school and other levies.
Can you work out your own tax rate from your bill?
Yes, and it takes a minute. Divide the total on your bill by your assessed value. In the example above, $3,750 divided by $500,000 gives 0.75%. Do the same on last year’s bill and this year’s, and you’ll see whether the rate moved, or just the assessment. If the two rates are close and your bill still jumped, look for a change to the property, like an addition, that MPAC picked up.
How do you read a property assessment notice?
Pull out the notice, grab a coffee and look at three things. First, the assessed value, which you compare with similar homes on your street, using their 2016 values, not current asking prices. Second, the property class, because a wrong class (residential, multi-residential, commercial) changes the rate you pay. Third, the description of the property, such as size, age and finished basement. Errors there are the ones that actually move the number.
If something’s wrong, MPAC offers a free Request for Reconsideration through its AboutMyProperty tool. We couldn’t confirm the filing deadline for your year, so read it off the notice itself before you rely on any date. Nobody charges you to ask. MPAC’s own page tells owners to read the notice carefully and let it know right away if they disagree with anything on it, and the notice itself spells out the deadlines.
Picture Ines in Hamilton, who finds her notice lists a finished basement she never had. She writes down the roll number, snaps a few photos of the basement as it really is, and files the reconsideration online. That kind of mistake is cheap to fix and easy to prove.
Assessment, appraisal and market value are three different numbers
An appraisal is one person’s opinion of value today, usually ordered by a lender or a seller. Market value is what a buyer pays. The assessment is a statutory figure with a fixed date. They’ll rarely match, and they don’t need to.
If you want a rough view of what your home has done since you bought it, use the home appreciation calculator with your purchase price and an estimate of today’s value. To see what a sale would leave after costs, the home sale proceeds calculator is the better tool. And if you’re buying, the closing costs calculator shows what sits on top of the price.
Mistakes that cost people money
The most common one is using the assessed value as a sale price when comparing offers. The second is ballparking next year’s tax from this year’s bill without asking whether the rate is moving. The third is ignoring a property class error for years because the bill “looked about right”.
And one limit of our calculator: it multiplies value by one rate. It doesn’t know about local levies, phase-ins, rebates or deferral programs, so enter the total rate from your own bill.
Where the facts come from
The valuation date, the roles of MPAC, the municipality and the province, and the reconsideration process come from MPAC’s own pages, read in September 2026. The examples come from our property tax calculator. This site has no link with MPAC or any government body, and it can’t change your assessment for you.
Frequently asked questions
What is a property assessment?
It's the value a public agency gives your property for tax purposes. In Ontario, MPAC sets it as of a legislated valuation date.
What valuation date applies to my 2026 assessment in Ontario?
MPAC shows 1 January 2016 as the fixed date for 2026. The reassessment planned for 2020 was postponed.
Is my assessment what my house would sell for?
No. It reflects a past date, so it can sit far from today's price. Don't use it in place of an appraisal.
Can I challenge my assessment?
Yes. MPAC offers a free Request for Reconsideration through its AboutMyProperty tool. Check the notice for the deadline.
Does a higher assessment mean a higher tax bill?
Not always. What counts is how your change compares with the average in your property class and municipality, and what rate the council sets.
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