Ontario tenants sometimes agree, on an N10, to pay more than the rent increase guideline in exchange for something specific: new windows, a renovated kitchen, an added service. If the landlord takes the higher rent but never delivers, the tenant's remedy at the Landlord and Tenant Board (LTB) is the T4. Win it, and the Board can cancel the portion above the guideline retroactively and make the landlord refund what you overpaid.

Quick summary
Filed by Anyone who signed an N10 as tenant, including someone who has since moved out
When After the landlord falls short on the N10 undertaking
Time limit 24 months, counted from the increase's effective date
Filing Paper or email routes only (mail, courier, email, ServiceOntario); service on the landlord is done by the Board
Fee $53
After the order A Request to Review an Order, within 15 days

How N10 agreements work, and what a T4 does

The Residential Tenancies Act, 2006 (RTA), in s. 121, permits the two sides to agree on a raise above the guideline, paid for by particular capital work or by a service that is new or added. Section 121(2)–(5) attaches four conditions:

  1. The Board's N10 form must be used.
  2. The cap is the guideline plus 3% of the prior lawful rent.
  3. A written cancellation by the tenant inside five days undoes it.
  4. Six days must pass after signing before it can start.

Section 122(1) gives the tenant, or a former tenant, a right to apply where the landlord:

  • did not carry out an undertaking in the agreement, in whole or in part;
  • built the agreement on work the landlord said was done but was not; or
  • built it on services the landlord said were provided but were not.

Section 122(3) allows the Board to strike out part or all of the extra increase from its start date and to order a refund.

Is the T4 the right application?

Only where an N10 was actually signed. Otherwise:

Problem Application
A raise with no agreement behind it, or one over the guideline limit Apply on a T1
A service you had, which the landlord has since removed T3
An N10 increase where the promised work or service never came T4

Time limits

Two years (s. 122(2)). Once two years have passed since the increase kicked in, the door closes. The starting point is the N10's effective date; the day it was signed does not matter. Example: an N10 signed January 20, 2026 with an effective date of February 1, 2026 must be challenged by February 1, 2028.

Rent history. The form asks for the last two years of rent, or since move-in if that is shorter.

Completing the T4

The current version is dated 01/04/2022.

Part 1. Address of the unit; names and contact information for each tenant; the landlord's name and address; file numbers of related cases.

Part 2. This is your explanation, in four pieces:

  • the date of the increase and the amount it exceeded the guideline by;
  • the math: the guideline increase that was allowed, set against the increase you agreed to; the gap is the above-guideline amount;
  • which terms of the N10 the landlord did not meet;
  • your rent history for two years.

A worked example of the math. Rent was $1,800 a month. The 2026 guideline of 2.1% would have allowed $37.80. The N10 raised rent by 4%, or $72.00 (within the guideline plus 3%). The above-guideline part is $72.00 minus $37.80: $34.20 a month, or $410.40 over a year.

Part 3. Sign. The pages that follow cover accommodation or French-language needs and payment.

Filing

The T4 cannot be filed online through the Portal. Instead:

  • Mail or courier: 15 Grosvenor Street, Toronto, addressed to the LTB.
  • ServiceOntario: drop it off at a centre that handles LTB documents.
  • Email: send it to [email protected], then pay through the link you receive, which lapses in three calendar days.

It costs $53.

What each side should do

The tenant

  • Find your signed N10 and note the effective date; the two-year clock runs from it.
  • Gather proof of what was promised and what did not happen: the N10's description of the work or service and the completion date written on it, photos, emails asking about the work, and your rent receipts.
  • Claim the right amount. Only the above-guideline part can be recovered; the ordinary guideline increase is not touched.

The landlord

  1. Get out the signed N10 and look at its effective date. Two years past it, a T4 is out of time.
  2. Show the work or service was delivered. Capital work is proven with invoices, permits, sign-offs from contractors, dated photographs and notices of completion; a service, with records that it has run from the agreed start date.
  3. Document partial work. The Board's power extends to part of the increase, not just all of it, so evidence of whatever portion was completed still counts.
  4. Check the numbers. Was the right year's guideline used, and did the agreed raise respect the guideline-plus-3% cap? An overshoot invites a second challenge.
  5. Disclose evidence on time: a week ahead of the hearing, or five days ahead for reply evidence (Rules 19.1–19.2).

Why T4s fail

  1. Too late. Section 122(2) bars anything filed once two years have run from the effective date.
  2. No N10 in the picture. The T4 depends on a s. 121 agreement existing.
  3. Claiming the guideline portion. The ordinary guideline raise is safe; only the extra is recoverable.
  4. Silence on the broken promise. The tenant has to identify the specific N10 terms the landlord failed to meet.
  5. Wrong filing route or no fee. It goes by mail, courier, ServiceOntario or email, and the fee has to be paid.

After filing

A hearing is held and an order follows. When the tenant wins, it sets out the invalid portion and the refund. Either side can seek a review inside 15 days (for orders dated from July 1, 2026), or take a legal question to the Divisional Court inside 30 days (s. 210).

Common questions

How large can an N10 increase be?

Up to that year's guideline plus 3% of the rent previously lawfully charged (s. 121(3)).

Can a tenant back out of a signed N10?

Yes: give written notice within five days. Nothing takes effect until at least six days have passed after signing.

What does a successful T4 get the tenant?

Cancellation of some or all of the extra amount, effective from when it began, plus an order that the landlord refund the excess.

Does the landlord have a deadline to finish the work?

The N10 has a space for the completion date of the work, or the start date of the service, past or future. That date, and the details on the N10, are what the Board measures against what was actually delivered.

Official sources