Supplementary property tax bills

A supplementary property tax bill is an extra bill for tax that the regular annual bill did not include. It usually follows a change to the property after the assessment roll was completed, such as a new house, an addition or a change of use. Some provinces also use it to bill an assessment that was missed ("omitted").

The bill arrives on its own, outside the normal billing calendar. The City of Toronto says supplementary and omitted assessments "are billed separately from the regular billing cycle, and are issued throughout the year." Calgary says the tax bill "will be sent separately" from the supplementary assessment notice.

The extra tax is not a new kind of tax or a penalty. It is the same property tax, at the same rates, charged on value that was not on the roll when the annual bill was calculated. Manitoba's Municipal Act says supplementary taxes "must be calculated using the applicable tax rate or rates set by by-law for the year." Alberta's Municipal Government Act requires a council that passes a supplementary property tax bylaw to "use the tax rates set by its property tax bylaw as the supplementary tax rates to be imposed."

The names vary. Ontario uses "supplementary" and "omitted" assessments, British Columbia a "supplementary roll", and Québec law calls the extra amount a "supplément" of taxes.

Each province lists the events that allow an extra assessment. The common ones are new construction, an improvement, a change of use or class, and property that was left off the roll.

Ontario. Toronto says MPAC can provide supplementary or omitted values when "land is omitted from the assessment roll", the "use of the property changes", or the "property is improved due to construction, an addition, or renovation". Those assessments are issued under sections 33 and 34 of the Assessment Act.

Manitoba. A municipality may impose supplementary taxes if the assessor reports that the property "is liable to taxation but was not assessed", is taxable "due to change in ownership or use", needs a higher improvement assessment "because of a change in the physical condition of the improvement", has a changed classification, or "the land has been improved or subdivided" (s. 326(1)). These rules apply to a municipality "continued or formed under this Act" (s. 1); The City of Winnipeg operates under The City of Winnipeg Charter, which this guide does not cover.

Alberta. Supplementary assessments are optional for each municipality. Council must pass a supplementary assessment bylaw, and a bylaw or amendment applies to a year "only if it is passed before May 1 of that year" (s. 313). The assessor then assesses improvements that are completed, occupied or moved into the municipality during the year (s. 314(2)).

British Columbia. The assessor must put property on a supplementary roll if it "was liable to assessment for the current year, but has not been assessed on the current roll" or was assessed "for less than the amount for which it was liable" (Assessment Act s. 12(2)).

Québec. A change to the assessment roll that adds or changes an assessment unit or an entry used to calculate a tax leads to a supplement owed by the person in whose name the unit is entered (Loi sur la fiscalité municipale, art. 245).

The extra value is taxed at the normal rates, but only for the part of the year after the change. The supporting assessment notice usually shows the date the change took effect.

Ontario. The tax on a supplementary assessment is "the amount of taxes that would have been levied for the portion of the taxation year left remaining after the change occurred if the assessment had been made in the usual way" (Assessment Act s. 34(1)). Toronto describes the residential bill as the supplementary or omitted assessment value multiplied "by the tax rate for the applicable tax year."

Alberta. Supplementary assessments are prorated "to reflect only the number of months during which the improvement is complete, occupied, located in the municipality or in operation, including the whole of the first month" (MGA s. 314(4)). Calgary calculates the bill as the assessed value multiplied by the tax rate(s), "divided by 12 months in the year, multiplied by the supplementary months". Its example: if the number of supplementary months is 3, "the billing is for the months October, November, and December."

Québec. The supplement is the tax payable on the amended roll, "proportionnellement à la partie de l'exercice financier municipal ou scolaire non encore écoulée" when the change takes effect, compared with the tax already paid for that year (art. 245). If the change lowers the value, the result is a refund. A refund owed after a roll change under article 174 or 182 must be paid within 30 days of the roll change (art. 247 and 249).

The how property tax is calculated guide explains the basic value-times-rate formula these bills use.

The look-back period is set by provincial law and differs a lot.

Ontario: omitted assessments can reach the current year and the two years before it. Section 33 of the Assessment Act covers land omitted "for the current year or for all or part of either or both of the last two preceding years". A supplementary assessment under section 34 is taxed for "the portion of the taxation year left remaining after the change occurred". Toronto says MPAC "has authority to assign omitted and/or supplementary assessment for the current year and two years prior." One bill can therefore cover more than one tax year.

Manitoba: supplementary taxes start on the date of the change, "but not earlier than January 1 of the year preceding the year in which the assessor's report was received by the municipality", and end on December 31 of the year the report was received (Municipal Act s. 326(3)).

British Columbia: the assessor can go back to a previous year only if the missed or low assessment is due to an owner's failure to disclose, an owner's concealment of particulars, or a missing or incorrect return (Assessment Act s. 12(3)). Separately, the assessor may correct errors and omissions on a supplementary roll "at any time before December 31 of the year following completion of the assessment roll" (s. 12(4)).

Alberta: supplementary assessments cover improvements completed, occupied, moved in or operational in the year they are taxed (MGA s. 314).

Québec: the supplement is based on the part of the fiscal year left when the roll change takes effect (art. 245). The rule does not apply to school tax when the roll change comes into force during that school year.

The due date is printed on the bill, and it is usually later in the year than the regular due dates. Some provinces also give a grace period before penalties can start.

- Toronto: supplementary and omitted bills "are due in two installments, regardless, of the number of years for which you are billed." They "cannot be paid through the Pre-Authorized Tax Payment program", so payment must come by another method. - Calgary: the bill "must be paid on or before the due date shown on the bill" to avoid penalties. For owners already on the monthly Tax Instalment Payment Plan (TIPP), the instalment "is recalculated when the supplementary tax is billed". - Saskatoon: "Supplementary Tax Notices are due on December 31 of the year they are issued." - Manitoba: no penalty may be charged on supplementary taxes "for the first 90 days" after the notice is sent, compared with 30 days for other taxes (Municipal Act s. 346(4)). - British Columbia municipalities: "30 days' notice must be given for payment of those taxes and a penalty must not be added in that period" (Community Charter s. 241(1)). - Québec: a municipal supplement resulting from a roll change the assessor makes under article 174 must be paid within the delays set under article 252 of the Loi sur la fiscalité municipale, and it bears interest at the same rate as the tax once that delay expires (art. 246).

General payment methods are covered in how to pay property tax.

Yes. A supplementary assessment can be reviewed or appealed, but the deadline is usually tied to the notice date rather than the annual appeal window.

- Ontario: a person who received a notice under s. 35(1) may ask MPAC to reconsider the assessment "no later than 120 days after the issuance date on the notice of assessment" (Assessment Act s. 39.1(3)). Toronto adds that supplementary and omitted bills must still be paid "as issued, to avoid incurring any penalty/interest." - British Columbia: a complaint must be filed with the assessor by January 31 of the year after the roll is "completed under section 3 or changed or amended under section 12" (Assessment Act s. 33(2)). If an assessment on a supplementary roll is set aside or reduced, the collector must refund the excess tax, penalty and interest (Community Charter s. 241(2)). - Manitoba: a taxpayer named in a supplementary tax notice may apply to the board of revision about liability, assessment or classification. The application must be in writing and filed "within 30 days after the day of mailing of the supplementary tax notice" (Municipal Act s. 328). - Alberta: the supplementary assessment notice must show the notice of assessment date and state that a complaint may be filed "not later than the complaint deadline" (MGA s. 316.1).

See the provincial pages for Ontario, British Columbia, Alberta and Manitoba assessment appeals.

Owners of newly built homes can receive supplementary bills when the house is finished or occupied partway through a year that was billed on land only.

Toronto says: "If you own a new property, the first regular bill you receive from the City may only be for the portion relating to land value. You should expect a supplementary and/or omitted bill for the structure to follow." Because Toronto says MPAC can assign these assessments for "the current year and two years prior", the first bill for the structure can cover more than one year.

Toronto also notes that the City "cannot project the assessed value for your new property", since MPAC sets it. For planning, its page suggests using "the purchase price as an estimated assessed value" and multiplying it by the year's tax rate. The bill itself is based on the value MPAC assesses.

In Alberta, Calgary sends a supplementary assessment notice for new construction or improvements "completed or occupied during the current tax year" that were not on the annual roll. The notice includes the supplementary months and the date the supplementary is based on.

The property tax adjustment at closing guide covers how the year's tax is usually split between buyer and seller.