The brand is inviting people to trade in their knick-knacks for a bar of Dairy Milk in a pop-up shop in Soho.
It is designed to tie in with its latest ad "Mum’s birthday" by VCCP which shows a little girl buying chocolate for her mum with the little things she has in her purse such as buttons and a plastic ring.
Benazir Barlet-Batada, brand equity lead at Cadbury, told Campaign: "The ad itself is a way to show small acts of kindness and generosity in the real world and tying in this real-life experience is a way to show and give generosity back to the real people of Britain."
The brand has also invited YouTuber stars to film and promote the pop-up to help the brand reach a younger audience too.
If you're in need of a junk clear-out, the "Glass and a half" shop is open all weekend.