Rent increases in the ACT: how often, how much, and how to challenge one

How often rent can go up

A rent increase can only take effect at least 12 months after (section 64AAA):

• the day your tenancy started, for the first increase, or
• the day your last increase took effect.

Since 10 December 2024 this also covers a new lease with the same tenant: the 12 months runs from the last increase, even if it was under your old lease. The limits stop applying only when an entirely new set of tenants moves in.

How much notice you must get

Your lessor must give you 8 weeks’ written notice (section 64B). The notice must state:

• the day the increase takes effect (at least 8 weeks after the notice)
• the amount of the increase
• whether it’s more than the prescribed amount, and if so, that without your agreement it can only happen with ACAT’s prior approval

The ACT Government’s Renting Book says an increase isn’t valid unless it follows these rules or ACAT approves it. Keep a record of the date you received the notice.

How much rent can go up: the prescribed amount

The ACT doesn’t ban increases above a set percentage. Instead, the law sets a prescribed amount:

• An increase at or below it is presumed not excessive. You can still challenge it, but you have to show it’s excessive.
• An increase above it can only happen if you agree in writing after getting the notice, or ACAT approves it first. If it goes to ACAT, the increase is presumed excessive unless the lessor shows otherwise.

The prescribed amount is 110% of the rise in the rents part of Canberra’s Consumer Price Index since your last increase was notified (or since the tenancy started). The formula is in section 5A of the Regulation:

1.1 × current rent × (current index − initial index) ÷ initial index

Both index figures depend on the dates notices were given, not the dates increases started. If the index has fallen, any increase is above the prescribed amount.

Check yours with the ACT rent increase calculator. The ACT Government’s own calculator is offline while it’s updated for the ABS’s switch to a monthly CPI in November 2025.

Fixed-term leases

• Signed before 10 December 2024: rent can’t go up during the fixed term unless your lease sets out the increase or a way to work it out (section 64A). A lease like that can allow an increase above the prescribed amount.
• Signed on or after 10 December 2024: an increase can take effect during the term, subject to the 12-month rule, 8 weeks’ notice and the prescribed amount.
• Renewing: a new lease with at least one of the same tenants is a “consecutive tenancy agreement”, and the rules above apply to the new rent. Your lessor can’t charge you for renewing (section 15).

Challenging an increase at ACAT

1. Apply at least 2 weeks before the increase is due to start (section 64C). ACAT can accept a late application in special circumstances.
2. Use ACAT’s “application for resolution of a tenancy dispute” form. See how ACAT tenancy applications work for fees and exemptions.
3. The rent stays the same while your application is pending, unless ACAT allows the increase.
4. ACAT decides. It can allow the increase, allow a smaller one or disallow it. It looks at the rent before the increase, when and how much it last went up, the lessor’s costs, the state of repair, what’s supplied with the home, rents for comparable homes and anything else relevant (section 68).

If ACAT has reviewed an increase, any further increase within 12 months of the date it would have started is void.

You don’t have to agree

You don’t have to sign anything agreeing to an increase above the prescribed amount, and it isn’t your job to go to ACAT to stop it: the lessor needs ACAT’s approval first. A lessor can’t end your tenancy because you won’t agree to an increase.

If you’d rather move, you can give 3 weeks’ notice to leave before the increase starts.