You served the N1, the tenant kept paying the old rent, and now you are at the LTB asking for the difference. Then the member points to one wrong date on the form and the whole notice is void. This is one of the rent increase notice mistakes Ontario landlords make most often, and when it happens you start over, and the clock restarts at 90 days.
I have watched this happen to Hamilton landlords who did everything else right. The rules on an N1 are simple, but the LTB enforces them exactly as written. Here are the rent increase notice mistakes in Ontario that we see most, and how to avoid each one.
Mistake 1: counting the 90 days wrong
An N1 must give the tenant at least 90 days’ notice before the increase takes effect. The count starts on the day the tenant is deemed to receive it, not the day you sign it.
Hand delivery or a mailbox drop counts as served that day. Regular mail adds five days. Email only counts if the tenant has agreed in writing to receive notices that way.
We took over a fourplex in Ward 3 where the previous owner mailed every N1 exactly 90 days out. Every one of them was short by five days. Nobody caught it until a tenant disputed the increase and the LTB agreed. The owner lost a full quarter of the increase, on four units.
Build in a buffer. We serve at 100 days or more.
Mistake 2: picking the wrong effective date
The new rent has to start on the first day of a rental period. If rent is due on the 1st, the increase starts on the 1st. An effective date of the 14th is a defective notice, even if it is 120 days out.
This one trips up landlords with mid-month move-ins. Check the lease for the actual rental period, not the calendar you assume.
Mistake 3: increasing before 12 months have passed
You need 12 months since the last increase, or since the tenant moved in if there has been none. The 90-day notice does not shorten that. If a tenant moved in on March 1, the earliest new rent date is the following March 1, and your notice has to be served at least 90 days ahead of that.
Watch out when you buy a building. The 12-month clock does not reset on a sale. Ask the seller for the date of each tenant’s last increase, in writing, before closing.
Mistake 4: going over the guideline without an approved AGI
The 2026 guideline is 2.1%. For 2027 it is 1.9%. You can confirm the current figure on the Ontario rent increase guideline page.
If you serve an N1 for 4% on a unit covered by rent control, you have not asked for 2.1% plus a bit extra. You have served a notice for an increase the tenant does not have to pay. Anything above the guideline needs an approved above-guideline increase from the LTB, which is a separate application with its own evidence. Our Ontario rent increase guideline guide walks through the N1 step by step.
One exception matters in Hamilton. Units first occupied for residential use after November 15, 2018 are exempt from the guideline. That includes many newer builds and some conversions on the Mountain and in the downtown core. You still have to give 90 days’ notice and follow every other rule.
Mistake 5: wrong names, wrong form, wrong details
The tenant names on the N1 must match the lease. If two people signed and you name one, expect a challenge. Use the current version of the form from Tribunals Ontario, and fill in the unit address exactly as it appears on the lease.
Also check the math. The N1 asks for the old rent, the new rent and the percentage. If those three do not agree, the LTB will not fix it for you.
Mistake 6: no proof of service
If a tenant says they never got it, you need to show they did. Keep a signed Certificate of Service for every N1, with the date, method and who delivered it. Take a photo of the delivery if you use a mailbox. This takes two minutes and is the difference between winning and losing a dispute.
What a void N1 actually costs you
A void notice does not just delay the increase. The tenant keeps paying the old rent, and if you later file an N4 for the unpaid increase, that application falls apart too. You cannot claim arrears the tenant never owed. It is one of the rent increase notice mistakes Ontario landlords regret most.
On a $1,850 unit with a 2.1% increase, that is about $39 a month. Over a year of delay, that is $466 lost on one unit. Across a 12-unit building it is more than $5,000, plus the time you spend at the LTB. If a dispute does escalate, our landlord legal services team handles LTB filings for owners.
A simple checklist to avoid rent increase notice mistakes Ontario landlords make
- Twelve months since the last increase or move-in date
- Effective date is the first day of a rental period
- At least 90 days after the deemed service date
- Percentage is at or under the guideline, or the unit is exempt
- Tenant names, unit address and rent figures match the lease
- Current N1 form
- Certificate of Service signed and filed
How we handle this at Found Spaces
We manage more than 600 rental units across Hamilton and the surrounding area. Every N1 we serve goes through the same checklist, and we track increase dates for every tenant in a single system so nothing goes out early. That is boring work, and it is why our notices hold up. It is also why the rent increase notice mistakes Ontario landlords make most often do not happen on our watch.
If you are managing your own units and are not sure your dates are right, we are happy to look over your rent roll. You can read more about our rental property management services or send us a note at the address below.
Kate Mackay
Kate Mackay is the founder and CEO of Found Spaces Property Management, managing over 600 rental units across Hamilton, Stoney Creek, Ancaster, Dundas, and the greater Hamilton area. She built Found Spaces from the ground up starting in 2017 and specializes in full-service property management for residential landlords and real estate investors.
