The date of manufacturer is marked on all new helmets sold legally in the UK. This is important information because a helmet could have been on the shelf in a shop for two years, in which case you would need to think about replacing it within 3 years. Y
ou can check the date of manufacture, it is normally on the outside of the helmet, or on a label on the chin strap, or the date may be on a sticker inside the helmet, under the lining.