ACT Rent Increase Rules Explained — What Every Canberra Landlord Needs to Know in 2026
Confused about ACT rent increase rules? Jaira Properties explains the CPI cap, how to serve a valid notice, and what "excessive rent" means at ACAT. Updated for 2026.
If you own a rental property in Canberra, understanding how and when you can increase rent is one of the most important things you need to get right. The ACT has some of the most specific rent increase rules in Australia — and getting them wrong can mean your increase is unenforceable, or worse, challenged at the ACT Civil and Administrative Tribunal (ACAT).
This guide explains exactly how the rules work in plain English.
How often can you increase rent in the ACT?
Under the Residential Tenancies Act 1997 (ACT), rent can only be increased once every 12 months for the same tenancy. This applies regardless of whether the tenant is on a fixed-term or periodic agreement. You cannot increase rent more frequently than this, even if the lease is renewed.
How much notice must you give?
You must give your tenant at least eight weeks written notice before a rent increase takes effect. The notice must state the new weekly rent amount and the date it takes effect. A verbal notice or an informal text message is not sufficient — it must be in writing.
What is the CPI cap and how does it work?
The ACT introduced a rent increase guideline linked to the Consumer Price Index. If your proposed increase exceeds the CPI-based guideline figure published by the ACT Government, the increase may be considered "excessive" and your tenant has the right to challenge it at ACAT.
This does not mean you are prohibited from increasing rent above the guideline. It means your tenant can apply to ACAT for a review, and ACAT will assess whether the increase is excessive having regard to market rents for comparable properties, the landlord's costs, and other relevant factors.
For 2025, the guideline figure was approximately 10% — though this fluctuates each year based on ACT CPI movements. Always check the current ACT Government guideline before issuing any rent increase notice.
What counts as an "excessive" rent increase at ACAT?
ACAT considers an increase excessive if it is above the guideline AND cannot be justified by market evidence or a material change in the landlord's costs (such as a significant rates increase, land tax movement, or insurance premium change). If ACAT finds the increase excessive, it can set a lower amount that applies instead.
The practical takeaway: if you are increasing rent by more than the guideline figure, make sure you have evidence to support it — a current market rent appraisal is the most useful document you can have.
What Jaira does for our landlords
At Jaira Properties, we conduct a rent review for every property we manage at least once per 12 months. We compare your current rent against current market data, advise you on the appropriate increase amount, prepare the written notice, and serve it to your tenant correctly and on time. If a tenant challenges an increase at ACAT, we represent you throughout the process.
If you are currently self-managing or with an agency that does not proactively review your rent, you may be leaving money on the table every single year.
Ready to find out what your Canberra property should be achieving?
Contact Jaira Properties today for a free rental appraisal. We will tell you exactly what your property is worth on the current market and whether your current rent is keeping pace.
Jaira Properties — Canberra's property management specialists. ACT Licence No. 18404216.
Disclaimer: This article is general information only and does not constitute legal advice. For advice specific to your situation, consult a licensed property manager or legal practitioner.