I think it is 6 years from the date of manufacture (which should be on the bottom or side of the seat). I know some will now say when they expire right on the seat. They all expire due to the plastic breaking down from temperature changes over time.
Also, if the car seat has been in an accident it is not safe to use.
dh Andy of 11 wonderful years
ds Theodore is 7 (Nov '05) 4lbs 10 oz, 18.5 inches @ 37 weeks
ds Zachariah is 5 (Jan '08 ) 5lbs 4 oz, 19 inches @ 38.5 weeks
dd Annabeth (Aug 2 '13) 7 lbs 5 oz, 19.75 inches @39.5 weeks
some advice from a BTDT mom... I've tried a few different brands and types over the years - I found that using the infant car seat for it's ability to move around wasn't worth it for us. carrying that thing is the worst thing you can do for your body! And I didn't use it in and out of the stroller enough to make it worth it. I also didn't like leaving baby in there so long and I found that if I started from the very beginning to take them out and transfer them, they stayed asleep through the transfer - whether I was transferring to a stroller, sling, or straight into bed.
We are definitely going to skip the infant seat this time (our last one went through DS3 and 4) and go for a convertible. Especially since my babies tend to stay small for a long time, it's worth it for us to get that style because they can stay in it till they are at least 2, RF and FF...
just remember that baby gear is the biggest marketing racket out there! make sure you are really going to need a baby item before you succumb to buying it! for our first we had every bit and piece and by #3 we already realized how little you actually need to care for a baby! there's my 2 cents!
~Ayelet & Yoram
NJ, USA to Israel 12/29/08
Welcome baby boy!! 26.7.13
Rambling on at http://milkandhoneymomma.blogspot.com
facebook and twitterID: ayeletschwell
Thanks for answering my question! I'll do some research on the used ones we have and see what the situation is...
Ayelet - I have to agree... and it's encouraging to hear from a BTDT mama that we really don't need every little thing lol, especially since we're on a super tight budget right now