Miss October and You Miss 2027: The Rent Increase Notice Window

There's a specific sequence to raising rent in Ontario, and it's unforgiving about dates. If you get the timing wrong, the increase is simply invalid — you can't charge it, and you can't backdate it. By the time most landlords think about a January increase, the window has already closed. Here's the timeline and the rules behind it.

The October deadline, worked backwards

The vast majority of Ontario leases run month-to-month or align to the first of the month. If you want a new rent to start on January 1, 2027:

* "Early" means the first days of the month — count 90 days forward and confirm. If you're serving mid-month, the effective date shifts with it.

How much can you raise it?

For units covered by Ontario's rent control, increases are capped at the annual rent increase guideline. For 2026 that guideline is 2.5%. The guideline for 2027 is set by the province and should be confirmed before you serve notice.

Important exceptions: rent control does not apply to units first occupied for residential purposes after November 15, 2018. For those units, the guideline cap doesn't apply — but you still must give 90 days' notice on the correct form. Many newer Ottawa rental buildings fall into this category, which is why the distinction matters.

The most common mistakes

• Wrong form. Use Form N1 for standard rent increases. Form N2 is for units exempt from the guideline. Using the wrong form invalidates the notice.
• Insufficient notice. Serving on October 15 for a January 1 increase is not 90 clear days. Always count forward and add a buffer.
• Increasing more than once in 12 months. Ontario allows only one increase per 12-month period per unit.
• Applying above-guideline increases incorrectly. Above Guideline Increases exist but require an application to the Landlord and Tenant Board and are only granted in specific circumstances.
• Not keeping proof of service. If a tenant disputes receiving notice, you need evidence of how and when it was served.

Why landlords miss this

It's rarely incompetence — it's that the notice period is much longer than most people assume. A landlord who decides in December to raise rent for January has already lost the window and must wait months. Diarising the deadline a quarter ahead is the entire game.

Managed properties avoid this by default, because the notice calendar is tracked as a standing process rather than remembered ad hoc. If you'd rather not track it yourself, this is one of the more concrete things professional rent management takes off your plate. For the fuller picture on obligations and forms, see our guide to Ontario landlord laws and our breakdown of the Ontario rent increase rules.

This article is general information for Ontario landlords and is not legal advice. Confirm current guideline figures and form requirements with the Landlord and Tenant Board or a qualified professional before serving notice.