Understanding Ontario Rent Increase Rules is important for both landlords and tenants. Imagine receiving a rent increase notice and wondering whether the amount is legal. The first step is knowing the basic rules. In most rent-controlled rental units, landlords can increase rent once every 12 months, and the tenant must receive at least 90 days’ written notice using the proper Landlord and Tenant Board form. For 2026, the rent increase guideline is 2.1%. This is the maximum increase for most covered units without approval from the Landlord and Tenant Board. However, not every rental unit is covered by the guideline. Many units first occupied for residential purposes after November 15, 2018 may be exempt from rent control, although the 12-month and 90-day notice requirements generally still apply. Some above-guideline increases may also be allowed with Board approval. Tenants should review notices and keep copies of rent records. Landlords should check the unit’s status and follow the correct process before changing rent. A small mistake can lead to a dispute. Understanding the rules helps everyone make informed decisions and avoid stress.