Ontario A4 Form: Challenging a Rent Reduction Triggered by Lower Property Taxes

In Ontario, Form A4 asks the Landlord and Tenant Board (LTB) to change the size of a rent reduction that the law imposes when a building's municipal property taxes go down by a meaningful amount. Once the tax cut passes 2.49%, rents drop automatically under a set formula that the municipality applies, and the A4 is the route for a landlord (or tenant) who says that percentage does not fit the building.

At a glance

The purpose of the A4

Section 131 of the Residential Tenancies Act, 2006 (RTA) provides that when municipal property tax on a residential complex goes down by more than 2.49%, the lawful rent of each unit goes down with it, automatically. The cut is effective December 31 of the year in which the tax reduction takes effect (O. Reg. 516/06, s. 41). The size of the cut equals the percentage tax decrease times 20% where the property is in the multi-residential class, or times 15% for any other property. Where a complex has seven or more units, the municipality has to notify the landlord between June 1 and September 15, and the tenants between October 1 and December 15, using a Notice of Rent Reduction.

Under s. 132 and s. 42 of O. Reg. 516/06, either a landlord or a tenant may ask to vary that figure. There are four permitted grounds, and they line up with the four reasons printed on the form. If the application succeeds, the Board fixes the percentage reduction in an order.

One category of building is outside the A4 altogether. Units exempt from the rent rules by s. 6.1 (buildings, additions or certain second units first occupied for residential purposes after November 15, 2018) are not covered, since s. 132 is one of the sections that does not apply to them.

Choosing the A4, and spotting the wrong form

Other municipal charges (Reason 1). In the base year the municipality billed you charges it left out of the calculation. Special levies and user fees such as garbage collection may be included. Penalties, interest and fines, inspection charges, emergency or by-law repair charges, capital-work charges and the cost of vital services may not.

A different tax-to-revenue ratio (Reason 2). The formula assumes your taxes equal 20% (multi-residential) or 15% (other) of the complex's yearly rent revenue. If the true figure is different, the Board recalculates with your actual rent revenue. Landlords whose taxes are a smaller slice of revenue than presumed often gain.

A mistake in the notice (Reason 3). The Notice of Rent Reduction misstates either the tax decrease or the resulting rent reduction.

A later change to base-year taxes (Reason 4). After the notice, but before March 31 of the year after the reduction took effect, the base-year taxes went up or down, for instance because of a reassessment or a tax appeal.

The A4 is the wrong tool in two situations. A tenant who wants a reduction under s. 133 because municipal taxes and charges went down files the tenant's Rent Reduction application (Form T3), not an A4. A landlord whose taxes rose is looking at an above-guideline increase on an L5 instead.

The filing deadline and other time limits

Your application must be filed no later than whichever of these dates falls later:

1. the date 90 days after you were given the Notice of Rent Reduction (or, for a complex under seven units where no notice is required, 90 days after the tax notice effecting the decrease was issued); or
2. March 31 of the year following the year the rent reduction takes effect (O. Reg. 516/06, s. 42(2)).

The regulation counts the 90 days from when the applicant was "given" the notice; the form and instructions count from when the municipality "issued" it. Count from whichever is earlier.

For example, suppose a landlord receives a Notice of Rent Reduction on August 4, 2026 for a reduction that takes effect December 31, 2026. Ninety days from August 4 is November 2, 2026. March 31 of the following year is March 31, 2027. The later date, March 31, 2027, is the deadline.

No extension is available. The Board's power to extend time does not reach prescribed time requirements, and s. 132 is not among the applications whose filing deadline it may extend (RTA s. 190). If you mail the application, keep in mind that it counts as filed only on the fifth day after mailing that is not a holiday (Rule 4.8).

The Board can direct you to serve the application on the other parties (Rule 5.2). In a written hearing, service is due within 20 days of the Board issuing the notice (Rule 5.6); in an oral hearing, at least 30 days ahead of the hearing date (Rule 5.7). The Certificate of Service is then filed within five days of service (Rule 5.15).

Completing the A4, part by part

The version in use is dated 01/04/2022. Parts 1, 2, 3 and 5 are always required; Part 4 is needed whenever you rely on Reason 2 or want the Board to look at revenue. Use block capitals, whether typed or handwritten. The A4 instructions explain each box.

Part 1: General Information

• Applicant Information. Shade "Landlord", then give your name or the company name, address, telephone numbers and email.
• Address of the Rental Unit, Building or Residential Complex. List the street address of every building in the complex the application covers, adding a page if there is not enough room.
• Other Parties to the Application. Shade "Tenant". When the application covers the whole building, put one tenant in this box and set out all remaining tenants and their unit numbers on a Schedule of Parties.
• Notice of Rent Reduction. A copy must be attached if the municipality sent you one.
• Related Applications. Give the file number of any application still outstanding.

Part 2: Information about Municipal Property Taxes

You need two years here. The base year is the calendar year in which the rent reduction takes effect (the year the tax went down). The reference year is the calendar year immediately before it. For each, enter the complex's total property taxes, counting only property and education taxes and leaving out special levies, user fees and penalties. Attach the tax bills or other proof for both years.

Part 3: Reasons for Your Application

Shade each reason you rely on, then supply what it needs:

• Reason 1 needs the total of the other charges for the base and reference years, with evidence.
• Reason 2 needs you to shade whether the complex falls in the multi-residential tax class, and then to fill in Part 4.
• Reason 3 needs a description of the error, why it is wrong, the percentage you say is right and the calculation behind it.
• Reason 4 needs evidence that base-year taxes changed, such as the reassessment or the appeal decision.

Part 4: Information about Rent Revenue

Enter the complex's total yearly rent revenue for the base year. For a Reason 2 claim this is not optional: the instructions state that the Board cannot consider the application without it. Be ready to prove the rents (O. Reg. 516/06, s. 44).

Part 5: Signature

Shade "Landlord" or "Representative", then sign and date. A representative also adds a Law Society number and contact information.

Filing the application

You have three routes:

• By email. Pay the $201 fee online by Visa or Mastercard (credit or debit). Within 24 hours, send the application, the notice, your evidence and the payment receipt to LTBpayments@ontario.ca, putting the receipt number and the address in the subject line.
• By mail or courier. Enclose a certified cheque or money order payable to the "Minister of Finance", or pay by card using the Credit Card Payment Form.
• In person. Bring it to a ServiceOntario location that takes LTB filings.

Fees are non-refundable (see the LTB fees page); you can also submit a Fee Waiver Request.

Errors that sink an A4

1. Filing after the deadline. The regulation fixes the date and the Board has no power to extend it, so a late application cannot proceed.
2. Relying on Reason 2 but leaving Part 4 blank. With no base-year rent revenue, the Board has nothing to recalculate with and cannot consider that ground.
3. Missing tax evidence or a missing notice. Section 44 of O. Reg. 516/06 calls for proof of taxes in both years, proof of other charges for Reason 1, proof of rents for Reason 2, and a copy of any notice you were given.
4. Including charges the regulation excludes. Section 41(2) leaves out penalties, interest, inspection and repair charges, capital-work charges and vital-service costs. Counting them taints the entire calculation.
5. Leaving tenants off the Schedule of Parties. Any service the Board orders, and the Board's own record, are built from that list. An unnamed or unserved tenant has never been told about the application, and Rule 5.17 allows the Board to adjourn or dismiss when service fails.
6. Charging the old rent while you wait. Section 131(2) makes the reduction effective by law, with or without a notice. Collecting the higher rent before any variation order exposes you to tenant applications for money taken illegally.

After the application is filed

An A4 can be decided on paper, since Rule 5.6 provides for written hearings. If you receive a notice of written hearing, serve it within 20 days; if not, you will attend an oral hearing. The resulting order fixes the percentage rent reduction, running from the s. 131 effective date (s. 132(4)). Bring rents into line with the order and refund or credit tenants for anything they overpaid. If you disagree with the result, any party may ask for a review within 15 days of an order issued on or after July 1, 2026 (Rule 26.5); see the request to review an order page.

Frequently asked questions

How large must a tax decrease be before rents go down?

More than 2.49% on the complex's municipal property tax. When that threshold is crossed, rents drop automatically as of December 31 of the year in which the tax reduction takes effect.

What formula sets the amount of the rent reduction?

You multiply the percentage tax decrease by 20% if the property is in the multi-residential class, or by 15% if it is not. A Reason 2 application asks the Board to replace that assumption with the complex's real rent revenue.

My building has five units. Will I get a Notice of Rent Reduction?

Probably not, because municipalities only have to send the notice for complexes of seven or more units. The reduction still applies to a smaller building, and the 90-day branch of the A4 deadline is counted from the tax notice instead.

Official sources

• Form A4 – Application to Vary the Amount of a Rent Reduction (PDF)
• A4 Instructions
• LTB Forms, filing and fees
• Residential Tenancies Act, 2006, ss. 131–132
• O. Reg. 516/06 (General), ss. 41–44
• LTB Rules of Procedure