• Property Inspections

Supplementary Assessment

What are Supplementary Assessments?

Supplementary assessment reflects the increase in value of a property where a new building is completed and/or occupied during the current tax year. 

How does Supplementary Assessment and Tax work?

When the increase in value of the new building has been determined, a supplementary assessment and tax notice will be sent to the property owner indicating the additional taxes for the year.

When is the Supplementary Tax Notice sent out?

Supplementary Assessments are levied only in the year the newly constructed building is completed. There are two supplementary notice mailings for the Town of Okotoks.  Property owners are required to pay the supplementary tax in full within 30 days of mailing.

How is Supplementary Tax calculated?

The Town of Okotoks calculates Supplementary Assessments as per the example below: 

Type of Property

Residential Single Family Home

Total Assessment (Annual & supplementary assessment)


Less annual assessment shown on the Assessment Notice


Supplementary Assessment


Improvement completed on pro-rated Supplementary Assessment

July 1st (= 6 months)

$200,000 x 6/12 months =


*The tax rate is then applied to the pro-rated Supplementary Assessment to calculate the taxes due on the Supplementary Assessment.


The Town of Okotoks Supplementary Assessments is based on typical market values with a valuation date as of July 1st of the previous year.

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