are lap belts legal in australia

Yes—lap-only seatbelts are legal to use where they were originally fitted and remain in good nick; they’re just not allowed in new passenger cars anymore.

Modern ADRs require lap‑sash (three‑point) belts for front and outboard rear seats, and most newer cars have three‑point belts for the centre rear as well.

You must not downgrade a lap‑sash position to lap‑only, and any retrofit or modification should be engineer-approved to meet ADRs and your state’s rules.

For kids: boosters generally need a lap‑sash; a harnessed child seat can use a lap belt if it has a top tether and is installed correctly—check the seat’s manual.

Legal doesn’t mean ideal: lap belts load the abdomen and spine, so a three‑point is markedly safer for adults.

If in doubt, confirm with your road authority or an accredited installer before spanners meet metal.