How long does a car seat last before it expires?

Yes, car seats really expire

Every car seat sold in the US carries a manufacturer-set useful life, typically 6 to 10 years from the date of manufacture. This is not a marketing gimmick. The reasons are physical and regulatory:

• Plastic fatigue. A car interior cycles from well below freezing to well above 130°F (54°C) summer after summer. Years of expansion/contraction cycles plus UV exposure make the shell and harness components more brittle — exactly the parts that must absorb crash energy.
• Standards move. Federal safety standards (FMVSS 213) and seat technology improve; a 10-year-old seat predates side-impact advances that are routine now.
• Parts and labels degrade. Harness webbing wears, labels with critical installation info fade, and replacement parts stop being made.

Where to find YOUR seat's expiration

Check, in order:

1. A white sticker on the seat shell (usually underneath or on the side) with the date of manufacture and often an explicit "do not use after" date
2. A date molded into the plastic of the shell
3. The manual, which states useful life in years from the manufacture date

Common manufacturer lifespans: many seats run 6–8 years; several current convertible models run 10 years. Always use the number on YOUR seat — never a generic figure.

Count from manufacture, not purchase

A seat made in 2024 that sat in a warehouse and was bought in 2026 has already used 2 years of its life. When buying, check the manufacture sticker in the store — a freshly-manufactured seat gives you the full window, which matters if you plan to use one seat across multiple children.

Replace after a crash — the NHTSA rule

NHTSA says to replace a car seat after a moderate or severe crash. After a minor crash you may keep the seat only if ALL five of these are true:

1. The vehicle could be driven away from the crash
2. The door nearest the car seat was undamaged
3. No one in the vehicle was injured
4. The airbags did not deploy
5. There is no visible damage to the seat

Fail any one → replace the seat. Many insurers cover car-seat replacement after a crash; ask before paying out of pocket.

The used-seat problem

An expired-or-crashed history is invisible on a secondhand seat. That is why every child-passenger-safety authority gives the same guidance: never use a seat of unknown history — unknown crashes, unknown storage, possibly missing parts or open recalls. A hand-me-down from a trusted relative with a known history and a valid date is fine; a garage-sale seat is not.

What to do with an expired seat

Cut the harness straps, mark the shell "EXPIRED — DO NOT USE", and put it in the trash or a trade-in program (several large retailers run periodic car-seat trade-in events that recycle the plastics). Cutting the straps prevents someone from rescuing it into service.

Check for recalls while you're at it

Register your seat with the manufacturer (the postcard or the online form — takes 2 minutes) so recall notices reach you automatically, and you can search existing recalls on NHTSA's site by brand and model.