Look for the manufacturer's tag, normally located at the foot of the mattress. The tag contains information such as the manufacturing company and the manufacturing date.
Call the manufacturer if the tag is missing. Provide the mattress’s series and model numbers if available. You may be able to attain a manufacturing date, or at least a range of years in which the company manufactured your particular model.
Look for visible signs. Although you may not be able to arrive at a specific date with this method, you can get a good estimate of the mattress’s age. Look for rips, stains or wear around the edge of the mattress, indications that a mattress has been around for a while. Look for dips or compression on the sides. A new mattress should spring back after sitting or lying on it.
Take note of the color of the mattress as well as the fabric’s pattern. Newer mattresses are often white or ivory, although some manufacturers use other colors.