Do booster seats have expiration dates - Century Breverra Contour Sport

Look Lon the bottom or side the expiry date will be there.

All 20 what? Do you have 20 children?!

Car seats may not be used after their expiration dates...

Most seats expire six years from date of manufacturer, some longer.

Contact the manufacturer to be sure. NEVER use an expired seat.

Most car seats expires six years after date of manufacture (even if it has been sitting in the box)..

The expiration date is usually six years after manufacture (not first use). An expiration date may be embossed into the back or bottom of the plastic shell.

Most car seats have a six year expiration from the date of manufacture (not first use). Some seats may have an expiration date on a label, or may have an expiration date embossed into the plastic. To be certain, call the manufacturer. In the USA, call 800-544-1108 (Dorel Juvenile Group).
There are several recalls on the 22-150 model. See www.carseat.org and click on "recalls."

You can find information about Graco car seat expiration dates, including for 1756269 here on the Graco Heart-to-Heart blog.
http://blog.gracobaby.com/2010/02/11/car-seats-have-expiration-dates-too/
The blog also provides information on how to find the expiration date on the car seat itself.

I'm sorry, I don't know if or where you can get the instructions. The vast majority of carseats expire after 6 years, though. I think 10 years is the max. and there are few of those on the market. If at all possible, I would recycle the seat you have and pick up a new booster seat.

there are no such thing as expiration dates for car seats but I would check with the manufaturer for recalls and also maybe consumer reports or the bbb

You can call Britax customer service and they may send one out to you. Since the car seat is expired though, they may give you some hassle.