The 'Kids Go Free' promotion will feature on packs of Milkybar, Smarties, Rowntrees Fruit Pastilles, KitKat two-finger, Breakaway and Blue Riband.
Countlines will feature one token while hanging bags will feature three tokens, and multipacks four tokens.
Children need to collect two tokens to take part in one of five activities, from swimming, dancing and bowling to tennis and martial arts.
The promotion is being supported with a media campaign including TV and radio.
Tel 0800 0730 200