Child seats and ISOFIX in used cars — what to check before you buy

If you're buying a family car used, child-seat fitment is a real-world inspection item that's often missed. ISOFIX (also called ISOFIT or LATCH depending on the brand) was made mandatory on new cars in Australia from 2014, but in 2026 there are still plenty of well-priced used cars that pre-date it.

Top-tether vs ISOFIX

• Top-tether anchor — has been mandatory in Australia for decades. Located behind the rear seat (parcel shelf, boot, or roof). All cars sold new in Australia have at least 2 (usually 3) top-tether points.
• ISOFIX (lower anchors) — two horizontal bars at the seat junction. Standard on every new car since November 2014. Required to use ISOFIX-compatible child seats.
• Both together — the safest and most convenient option. A correctly-fitted top-tether plus ISOFIX seat is the gold standard.

The pre-purchase check

1. 1.Count top-tether points in the rear — there should be 3 (one per rear seat).
2. 2.Confirm they're undamaged — no cracks in plastic, no missing covers, anchor bolts torqued.
3. 3.Check for ISOFIX bars between seat back and cushion — usually marked with the ISOFIX logo. Some manufacturers hide them under fabric flaps.
4. 4.Bring your own ISOFIX seat to the inspection if possible — fit it. Some cars (e.g. earlier Mazda 3) have very tight seat-back geometry that won't accept all seats.
5. 5.Front-seat ISOFIX: very rare in Australia. Not required for children under 7 to be in the back.

Retrofit reality

You generally cannot retrofit ISOFIX to a car that wasn't built with it — the chassis pickup points may not exist or may not be rated. A few aftermarket kits exist (Britax for specific Toyota and Ford models) but they're costly and not all states accept them. Better to buy a car that has it from factory.

NSW child seat law refresher

• 0-6 months: rearward-facing approved restraint.
• 6 months - 4 years: rearward OR forward-facing with inbuilt harness.
• 4-7 years: forward-facing with harness OR booster with adult lap-sash.
• 7+ years: may use adult lap-sash, but most paediatricians recommend booster to 10-11.
• Under-7s must travel in the rear if the car has 2+ rows of seats.

Common questions

Are 3 kids across a rear bench legal?

Yes if there are 3 lap-sash belts and 3 anchor points, and the seats fit physically. In practice, most mid-size SUVs/sedans don't fit 3 restraints across. Test fit before buying.

Can a 5-year-old sit in the front?

Only if all rear seats are occupied by under-7s with appropriate restraints. Otherwise, no.