What counts as an approved alarm
- A photoelectric sensor.
- Complies with AS 3786.
- Either hardwired to mains power, or a sealed 10-year lithium battery unit.
Got older ionisation alarms?
Homes that already had compliant ionisation alarms when the photoelectric rule began can keep them for now. We haven't confirmed the exact date that rule started, but the law is clear about when the old alarms have to come out.
The three triggers for replacing them
- An alarm stops working.
- The day before settlement, when the home is sold.
- The day before a tenancy starts, is renewed or is extended.
Where they go
NT law points to the Building Code of Australia for alarm positions, which depend on the type of building. If the usual spot doesn't work, for example because steam from a bathroom keeps setting one off, the alarm can go somewhere else that still warns the people inside.
Who tests what, and when
| Owner-occupier | Landlord | Tenant | |
|---|---|---|---|
| Testing and cleaning | Each alarm at least every 12 months | Each alarm within 30 days before a tenancy starts | Each alarm at least every 12 months during the tenancy |
| A failed alarm | Replace it immediately | Replace it before the tenancy, and test and replace it if needed once the tenant reports one | Tell the owner as soon as practicable |
| Flat backup battery in a hardwired alarm | Replace it | Replace it before the tenancy | Replace it during the tenancy |
Before a tenancy, the landlord also has to give the tenant written information on testing and maintaining the alarms.
The safety switch date that affects alarm jobs
On 28 May 2026 the NT replaced its safety switch regulations with a single rule that has a long lead time. From 1 December 2028, nobody may do electrical work on an NT home's installation, rentals included, unless an approved safety switch is installed. The only exceptions are connecting the home to electricity, and urgent or emergency work.
Hardwired alarm work is electrical work. If your switchboard has no safety switch (an RCD, which cuts the power fast when current leaks to earth), plan to have one fitted well before that date.
Paperwork and licences
After electrical work, the NT document is a certificate of compliance, due within 20 business days to the owner, the occupier, the person the work was done for and the Electrical Safety Regulator. Swapping a fitting for a similar one in the same spot that works the same way and draws no more power doesn't need one, so a straight hardwired alarm swap may not come with a certificate. Ask the electrician which applies to your job.
From 1 July 2026, NT electrical contractors who advertise must show their licensed or registered business name, that they're licensed under the Electrical Safety Act 2022, and their contractor licence number.
What you can do, and what's licensed work
You can
- Test and clean each alarm at least every 12 months.
- Swap a flat backup battery in a hardwired alarm. NT law says replacing a part designed for people without electrical training isn't electrical work.
- Check each alarm's manufacture date.
Leave to a licensed electrician
- Installing or replacing hardwired alarms.
- Fitting an approved safety switch where the home has none.
- Any other electrical work. Doing it unlicensed carries a maximum penalty of 500 penalty units in the NT.
If we owned an NT home
We'd swap any ionisation alarms for photoelectric ones now, rather than waiting for a sale, a lease or a failure to force it. Where they're hardwired, we'd have a licensed electrician do it and check for a safety switch on the same visit, since that becomes a condition of any electrical work from 1 December 2028. Then we'd test every alarm once a year, as the law already asks.
Want a specialist to sort it?
Tell us the job and your postcode. We match the licence-checked local electrician who does this kind of work, and they call you. No ring-around, and your number goes to them alone.