It sets your property tax bill for the year, it is based on a valuation date most owners misunderstand, and the window to question it is short. Reviewing it takes twenty minutes.
Every January the City of Calgary mails a property assessment notice to every property owner. It contains a single number — the assessed value of your property — and that number, multiplied by the tax rate set later in the year, becomes your property tax bill.
Most owners glance at it, note whether it went up, and file it. But there is a limited window each year in which you can ask questions and, if something is genuinely wrong, formally challenge it. Once that window closes, the number stands for the year.
Errors do happen — a basement recorded as developed when it is not, square footage that does not match, a garage that was demolished years ago, a lot size that is wrong. The City assesses hundreds of thousands of properties using mass appraisal, and mass appraisal makes individual mistakes.
This guide covers what the number actually represents, how to check it properly, and what the process looks like if you decide to take it further. If you would like a second opinion on whether your assessment is defensible, ask us — comparable sales analysis is what we do all day.
The City values every property in Calgary using mass appraisal — statistical models applied to sales data across neighbourhoods and property types, adjusted for characteristics like size, age, condition, lot, and location. Nobody walks through your house. The model works from the property details the City holds on file for you.
The assessment sets your share; Council sets the rate. Your property tax is roughly your assessed value multiplied by the tax rate established in the spring budget process. This is why an assessment increase does not automatically mean a proportionate tax increase — what matters most is how your property moved relative to everyone else's. If every home in Calgary rose 8% and yours rose 8%, your tax share is essentially unchanged.
Your notice and the City's assessment search show the characteristics on file: living area, year built, basement development, garage, lot size, and more. These drive the valuation. An error here produces an error in the number, and it is the easiest kind of problem to get corrected.
An overstated assessment means you pay more than your share, every year, until it is corrected. Twenty minutes in January is a good trade.
Your assessment reflects estimated market value as of July 1 of the year before the notice. The assessment you receive in January 2026 reflects what the property was worth on July 1, 2025 — not what it is worth in January 2026.
This is the single biggest source of confusion. In a market that moved after July, owners look at current listings and conclude the City has it wrong. It has not; it is answering a question about a date six months ago.
The physical characteristics used are those as of December 31 of the previous year. So if you finished your basement in November, that is reflected. If you finished it in February, it is not — it will appear on next year's assessment.
Any comparable sales you rely on must be relevant to the July 1 valuation date. A sale from last month is not persuasive evidence about a value six months earlier, particularly if the market moved in between. Sales clustered around the previous spring and summer carry weight.
Your purchase price is useful evidence — but only if the purchase happened reasonably close to the valuation date and was an arm's-length transaction. A purchase in the previous June is strong. A purchase last week says little about July of last year.
Sellers ask us this constantly. Your assessment is a mass appraisal estimate tied to a date up to eighteen months before you list. It knows nothing about your renovated kitchen finishes, your specific view, your lot's orientation, or what the market has done since. Homes routinely sell well above and well below assessment, and neither is unusual.
“It is listed above assessment” is not, by itself, an argument that a home is overpriced — nor does listing below assessment mean it is a bargain. The assessment is answering a different question, at a different time, with far less information than a proper comparative market analysis.
As a rough sanity check, and as a signal when it is dramatically out of line with comparable homes on your street — which is exactly the situation worth investigating, because it may indicate an error in the property details the City holds.
If you want to know what your home would actually sell for today, that is a comparative market analysis using recent sales, current competition, and the specifics of your property. We do them at no cost and no obligation — and we will tell you honestly if the answer is not what you hoped.
Log in to the City of Calgary's assessment search with the access code on your notice and read the property characteristics carefully. Square footage, basement development, garage, year built, lot size, bathroom count. This is where errors live, and a factual error is by far the easiest thing to have corrected.
The City's assessment search lets you look at other properties. Find homes genuinely comparable to yours — similar age, size, style, condition, and street — and compare assessed values, ideally on a per-square-foot basis. You are looking for a pattern, not a single outlier.
Not “is my assessment higher than last year?” but “is my assessment fair relative to comparable properties, as of July 1 last year?” Equity with comparable homes is the standard that actually matters, and an assessment can be both accurate in isolation and inequitable relative to neighbours.
During the review period you can contact the assessment department at no charge to ask how your value was determined and to point out errors. Many issues are resolved at this stage without any formal complaint. Have your roll number, your notice, and your specific question ready.
A factual error in the property record — wrong square footage, a basement recorded as developed when it is unfinished, a garage that no longer exists, an incorrect lot size. Assessment materially out of line with genuinely comparable properties. Condition issues the model cannot see, such as significant unrepaired damage or a property in substantially poorer condition than its neighbours. And a recent arm's-length purchase price close to the valuation date that is meaningfully below the assessment.
That your taxes went up. That you cannot afford the increase. That the tax rate is too high — that is a Council budget matter, entirely separate from your assessment. That your assessment rose more in percentage terms than you expected. And your opinion of value without evidence to support it.
You are arguing that the assessed value is wrong for the valuation date, or that it is inequitable compared with similar properties. Both need evidence: the property record, comparable assessments, sales data, photographs of condition issues, contractor quotes for significant defects.
A 2% difference from your own estimate is not worth pursuing — mass appraisal is not precise to that level and neither is any valuation method. A 15% overstatement, or a factual error about your basement, is absolutely worth raising.
Each year there is a review period of roughly sixty days from when notices are mailed — the exact deadline is printed on your notice, and it is firm. During this window you can contact the City's assessment team free of charge, ask how your value was arrived at, and raise errors. Many concerns are resolved here, and this is where you should always start.
If the review period does not resolve it, you can file a complaint with the Assessment Review Board, an independent tribunal. There is a filing fee, which is refunded if your complaint succeeds. The complaint must be filed by the same deadline printed on your notice — the review period and the complaint deadline are the same date, so do not use up the whole window on informal conversations.
You present evidence supporting a different value; the City presents evidence supporting its assessment. Come with comparable assessments and sales relevant to the July 1 valuation date, documentation of any factual error, and photographs or quotes for condition issues. It is an evidence-based process, not a discussion about fairness in the abstract.
For a typical residential property most owners handle this themselves — the process is designed to be accessible. Agents who take a percentage of your savings exist; read their terms closely, because a multi-year contract for a modest reduction is often a poor trade. We are happy to help you assess whether you have a case before you decide.
Market value as of July 1 of the previous year, using the property's physical condition as of December 31 of that year. So a notice received in January 2026 reflects what the property was worth on July 1, 2025. This is the most misunderstood part of the system — comparing your assessment to today's listings is comparing two different questions at two different times.
No. It is a mass appraisal estimate tied to a valuation date up to eighteen months before you might list, produced by a statistical model that has never been inside your home. Properties routinely sell well above and well below assessment. For an actual value, you need a comparative market analysis using recent sales and current competition.
Roughly sixty days from when notices are mailed in January, with the exact deadline printed on your notice. That same date applies to both the informal Customer Review Period and to filing a formal complaint with the Assessment Review Board, so do not spend the entire window on informal conversations. After the deadline the assessment stands for the year.
Contacting the City's assessment team during the Customer Review Period is free, and many issues — particularly factual errors in the property record — are resolved at that stage. Filing a formal complaint with the Assessment Review Board carries a fee, which is refunded if your complaint succeeds.
A factual error in the property record such as wrong square footage, a basement recorded as developed when it is not, or a garage that no longer exists. An assessment materially out of line with genuinely comparable properties. Significant unrepaired damage or condition issues the model cannot see. Or a recent arm's-length purchase close to the valuation date at a price meaningfully below the assessment.
No. The assessment sets your share of the tax burden; Council sets the rate through the budget process. Objecting to the rate, or to affordability, is a budget matter rather than an assessment matter. A complaint has to argue that the assessed value is incorrect for the valuation date or inequitable compared with similar properties, and it needs evidence.
It is useful evidence if the purchase was arm's length and occurred reasonably close to the July 1 valuation date. A purchase the previous June is strong support. A purchase last week says very little about what the property was worth six months earlier, particularly if the market moved in between.
Generally not. Mass appraisal is not precise to within a few percent, and neither is any other valuation method, so a difference under about 5% is rarely worth the effort. A difference over 10%, or any factual error in the property record, is worth raising — and the factual errors are usually the easiest to have corrected.
If you are not sure whether your assessment is defensible, we will look at the comparables with you before you decide whether to file — and tell you honestly if we think you do not have a case.
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