The T4 Application in Ontario: What Happens When Promised N10 Work or Services Never Arrive

Ontario's T4 is a tenant's claim at the Landlord and Tenant Board (LTB) for one situation: you agreed in an N10 to a larger-than-guideline increase in return for new work or a new service, and the landlord never delivered. For the tenant, it is a way to get the extra rent cancelled and refunded. For the landlord, it is a claim to answer with proof of what was actually done.

The T4 in brief

Who uses the T4, and what it does for each side

Tenants file it. It asks the Board to say that some or all of the rent above the guideline was never valid and to order the landlord to pay it back.

Landlords receive it. It puts the N10 promise on trial, so the landlord's job is to show the work was done or the service provided, in full or in part.

The N10 deal behind every T4

Section 121 of Ontario's Residential Tenancies Act, 2006 (RTA) lets the parties trade a bigger increase for a specified capital expenditure, or for a service that is new or added. The deal has limits (s. 121(2)–(5)):

• It must use the Board's N10 form.
• It may add, at most, 3% of the prior lawful rent on top of the guideline.
• The tenant has five days to cancel in writing.
• The earliest start is six days after signing.

The three grounds in s. 122(1)

The landlord is open to a T4 if they:

1. broke an N10 undertaking, fully or in part;
2. based the N10 on work they claimed was done but was not; or
3. based it on services they claimed to provide but did not.

A winning claim lets the Board void all of the above-guideline amount, or just some of it, back to its start date and order the money returned (s. 122(3)).

Check that the T4 is the right form

Run through this before you start:

• No N10? Then use a T1 for an increase taken without agreement or beyond what the guideline permits.
• Service given, then removed? See the T3.
• Only the extra matters. The ordinary guideline increase is outside a T4.

The two-year clock

• Section 122(2) shuts the door two years after the increase starts.
• Count from the N10's effective date; the signing date does not matter.
• You also need two years of rent history, or since move-in if shorter.

Example. Signed February 10, 2025; higher rent from March 1, 2025. File by March 1, 2027 (a Monday). The signing date is irrelevant.

Filling in the T4, step by step

Use the 01/04/2022 version and go part by part:

1. Part 1, General Information. Enter the rental unit address, the tenants' names and contact details, the landlord's name and address, and any related LTB file numbers.
2. Part 2, Explanation of your application. Give: - when the rent went up and the amount over the guideline; - your math: allowed guideline increase versus N10 increase; - the N10 terms that were not kept; and - two years of rent history.
3. Part 3, Signature. Sign, then complete the accommodation and French-language request page and the payment page.

Sample math. Lawful rent $1,800; the guideline permits $45; the N10 adds $95. The T4 targets the $50 a month above the guideline, not the $45.

Sending it to the Board

This one is paper or email only; the Portal will not accept it. Choose one:

• mail or courier to the LTB, 15 Grosvenor Street, Toronto;
• a ServiceOntario centre that takes LTB filings; or
• email to ltbpayments@ontario.ca and pay by the link you receive (it expires in three calendar days).

Budget $53 for the fee.

For tenants filing this: a checklist

• [ ] A copy of the signed N10, with the effective date circled
• [ ] Filing date falls within two years of that effective date
• [ ] Your calculation of the above-guideline amount
• [ ] A plain list of the N10 terms that were not met
• [ ] Two years of rent history (or since move-in)
• [ ] The $53 fee, paid through the channel you used to file

For landlords receiving this

1. Find the signed N10 and read the effective date. If the T4 came in more than two years after it, the application is late.
2. Collect proof. Capital work: invoices, permits, contractor sign-offs, dated photos, completion notices. A service: records that it has run since the agreed date.
3. Count partial work. The Board can void "some or all" of the increase, so an exact record of what was finished can shrink any refund.
4. Re-run the numbers. Check that year's guideline and that the N10 stayed under the guideline-plus-3% cap. An overshoot will likely be challenged too.
5. Disclose on time. Send your evidence 7 or more days ahead of the hearing; reply evidence needs 5 (Rules 19.1–19.2).

Why a T4 can fail

1. Late filing. Past the two-year mark, s. 122(2) bars it.
2. No N10 exists. No s. 121 agreement means the wrong application.
3. Claiming the guideline amount. Only the extra above the guideline is recoverable.
4. Vague complaint. The tenant must name the N10 terms that were broken.
5. Wrong channel or unpaid fee. Portal filings are not accepted, and the $53 must be paid.

After the T4 is filed

1. The LTB schedules a hearing and both sides present evidence.
2. The Board's order, if the tenant wins, states the invalid portion and the refund due.
3. On an order issued from July 1, 2026 onward, a review request must come within 15 days.
4. An appeal on a question of law goes to the Divisional Court within 30 days (s. 210).

Questions people ask about the T4

What is the largest increase an N10 can allow?

The guideline for that year plus 3% of the previous lawful rent, and no more (s. 121(3)).

I signed an N10 and changed my mind. Am I stuck?

No. A tenant can cancel in writing within five days of signing, and the agreement cannot start until at least six days after it was signed.

What can a tenant win?

The Board may declare the above-guideline amount invalid, in whole or in part, from its effective date, and order the landlord to refund the overpayment.

Did the landlord have to finish by a certain date?

The N10 records a completion date for the work, or a start date for the service. The Board compares that date, and everything else the N10 describes, with what actually happened.

Official sources

• Residential Tenancies Act, 2006, ss. 121, 122, 207, 210
• T4 Instructions
• T4 application (PDF)
• N10 – Agreement to Increase the Rent Above the Guideline (PDF)
• LTB Rules of Procedure, Rules 19, 26
• LTB Forms, filing and fees

Last reviewed October 31, 2026. General information, not legal advice for your situation. Always use the current version of the form from the LTB.