Supplementary Tax Bills

If you own a property in the City of St. Catharines, you may have to pay a supplementary tax bill if you have:

• Purchased a new property
• Made any physical changes to your property
• Changed the use of your property

What is a supplementary tax bill?

The Municipal Property Assessment Corporation (MPAC) assess properties that have seen a change in property value throughout the year. Based on the property value changes, MPAC issues a supplementary tax bill to the City which is then charged to your property.

When do you pay the tax bills?

Supplementary tax bills are billed separately from the regular billing cycle and are issued throughout the year. You will receive a Property Assessment Change Notice from MPAC to let you know ahead of time.

Bills are due in two instalments. Payments must be paid to our office on or before the due date to avoid penalty or interest rate charges on your tax bill.

If you own a new property, the first regular bill you receive from the City may only be for the portion relating to the land value. Expect a supplementary or omitted bill to follow.

How do you estimate your tax bill?

To estimate your tax bill on a new property, use our property tax calculator. You can also use your property's purchase price as an estimated assessed value and multiple that amount by the applicable year's tax rate.

How are they assessed?

MPAC will create supplementary or omitted assessment values for the City for the current tax year and two years prior when:

• Land is omitted from the assessment roll
• Use of the property change
• Property is improved due to construction, an addition, or renovation

How do you appeal your assessment?

If you disagree with your property assessment value given by MPAC, you may request a review. The deadline to submit your Request for Reconsideration (RfR) is 120 days from the issue date on the Property Assessment Notice.

The Assessment Act

The Assessment Act allows MPAC to add or make changes to the assessment of your property for the current year or from the past two years.