Child Car Seat
A child car seat lasts 6 to 10 years from its manufacture date — most carry a printed expiry — and it must be replaced immediately after any significant crash, whatever its age.
Why it expires
A car seat is moulded plastic and foam, and both age even in a garage. Temperature swings from a hot car to a cold winter make the shell brittle over the years, harness webbing loses a little strength, and safety standards move on. That is why most makers print an expiry — typically six to ten years from the date of manufacture — after which the seat is no longer guaranteed to perform in a crash.
Find the date
Look for a moulded date-of-manufacture stamp on the shell and, on many seats, a separate "do not use after" label. Count from manufacture, not from the day you bought it. A seat handed down from an older child or bought second-hand may already be near the end of its life — and one with no traceable history is best not trusted at all.
After a crash
Any car seat involved in a significant crash is replaced, even if it looks perfect: the structure may have absorbed forces you cannot see. Most manufacturers and safety bodies advise replacement after anything beyond a very minor knock, and many car insurers will cover a new seat. Age and accident history — not appearance — decide when a seat is done.