ACT rent increase calculator
Check whether a rent increase is above the amount ACT law presumes is reasonable, and whether you got enough notice. It works the limit out from the Canberra rents index the law uses. The calculation runs in your browser; your figures aren't stored or sent to us.
How the ACT rent increase limit works
ACT law sets a "prescribed amount" for rent increases (Residential Tenancies Regulation, section 5A). An increase at or below it is presumed not excessive; one above it is presumed excessive. The prescribed amount is:
1.1 × current rent × (current index − initial index) ÷ initial index
- The index is the rents part of the Consumer Price Index for Canberra, published by the Australian Bureau of Statistics (ABS).
- The current index is the latest one published on the day you're given notice of this increase.
- The initial index is the latest one published on the day you were given notice of your last increase, or on the day your tenancy started if there hasn't been one.
In plain terms, rent can go up by 110% of the rise in Canberra rents over that period. If Canberra rents rose 1.2%, the limit is 1.32%. If the index has fallen, any increase is above the limit.
The other rules for a valid increase
- 8 weeks' written notice stating the new rent, when it starts and whether it's above the prescribed amount (section 64B).
- No more than once every 12 months, counted from the day the last increase took effect, or from the start of the tenancy (section 64AAA). Since 10 December 2024 this also applies when you sign a new lease for the same home.
- Above the prescribed amount? The lessor needs your written agreement after giving you the notice, or ACAT's approval beforehand. You don't have to apply to ACAT to stop it.
If you think an increase is excessive
You can apply to ACAT to review any proposed increase, even one at or below the prescribed amount. Apply at least 2 weeks before it starts (section 64C). While your application is pending, the increase doesn't happen unless ACAT allows it. More in rent increases in the ACT.
Why some results show a range
On 26 November 2025 the ABS replaced its quarterly CPI with a monthly one, on a different base. If your tenancy started, or your last increase was notified, before that date, the law doesn't say how to compare the old index with the new one. The ACT Government's Renting Book uses the new monthly series for the month of the earlier date. A literal reading uses the quarterly figure published then, converted with the ABS's conversion factor. Where the two give different answers, this checker shows both. If your increase falls between them, get advice.
About the data
Index figures are ABS series A130395218J (Rents, Canberra, monthly, September 2025 = 100) and, for earlier dates, A2331871V (quarterly, 2011–12 = 100) with the ABS conversion factor 0.8033. The checker covers notices given from 26 November 2025 and has index data published up to 27 October 2026. It's updated after each monthly ABS release; if your notice is later than that, it warns you that a newer figure may apply. The ACT Government's own calculator is offline while it's updated for the monthly CPI.
This checker is general information, not legal advice. It doesn't check whether a notice was properly given or whether your lease has special terms. Fixed-term leases signed before 10 December 2024 can set their own increase.