Division 40 · hallways and bedrooms
Smoke alarm: effective life and depreciation rate
Each alarm is a separate asset. At $122 installed new, one costs $300 or less, so a sole owner can write it off in the year it is installed, unless it and identical alarms acquired in the same income year cost more than $300 together, as three do ($366).
- Effective life
- 6 yrs
- DV · PC rate
- 33.33% · 16.67%
- Installed new, 2026
- $122
Five years of a smoke alarm bought new
A smoke alarm costing $122, held for each full year, under each method. At $122 it costs $300 or less, so a sole owner deducts the whole cost in the year it is installed (section 40-80(2)), unless it is part of a set, or one of identical items, costing more than $300 together. No rate applies to it then.
| Year | Diminishing value 33.33% | Prime cost 16.67% |
|---|---|---|
| 1 | $122 written off in full | |
What a smoke alarm cost installed, by year
- 2000$75
- 2010$90
- 2020$102
- 2026$122
The effective life of a smoke alarm fitted new in a property built in 2020 ends in 2026, while the building's own capital works deduction runs to the 2059–60 income year: see depreciation on a property built in 2020.
Price is for one item, supplied and installed.
By dwelling type
Our dwelling pages price a smoke alarm with the typical plant of a house, a townhouse, a unit and an apartment in every state; two states of each:
- A house in Western Australia
- A house in Tasmania
- A townhouse in Queensland
- A townhouse in the Northern Territory
- A unit in Tasmania
- A unit in South Australia
- An apartment in the Australian Capital Territory
- An apartment in Victoria
Each is priced at its state's rates, and the state's own page sets the four types side by side: Victoria, Queensland, Western Australia, South Australia, Tasmania, the Australian Capital Territory and the Northern Territory.
Common questions
What is the effective life of a smoke alarm?
6 years, as the Commissioner of Taxation determines it for "Smoke" under "Alarms" in the residential property operators' table of the Income Tax Assessment (Effective Life of Depreciating Assets) Determination 2025, which most schedules use (an owner may estimate its own instead, section 40-105). One other item here shares it: curtains.
What is the depreciation rate for a smoke alarm?
33.33% a year under diminishing value (200% ÷ 6), taken from what is left of the value, or 16.67% under prime cost (100% ÷ 6), taken from the cost. At $122, though, one that is not part of a set, or of identical items, costing more than $300 together is written off in the year it is installed instead (section 40-80(2)). An item first held before 10 May 2006 takes 150% ÷ 6 under diminishing value.
Can I claim a smoke alarm that came with the property?
Generally not, for an individual, a self-managed super fund or most trusts and partnerships that bought an established property at or after 7.30 pm on 9 May 2017 (section 40-27; the 2017 rules set out who it reaches and the exceptions). Such plant is still valued, at what it costs new in the year the property is bought less its age and condition: for a smoke alarm 3 years old in good condition, about $61 of the $122 new in 2026, a value whose decline can make a capital gain or loss when it is sold or scrapped. For a smoke alarm bought new for the property while it is let, and never used while it was the owner's home, deductions start on the day of installation.
What does it cost to install a smoke alarm?
About $122 installed new in 2026, from our cost database, and about $90 in 2010. The other items here nearest it in price are an exhaust fan (about $128, with a 10-year life) and a water filter (about $167, with a 15-year life).
Other items
General information only, not advice about your circumstances. Speak to a registered tax agent before relying on it.