Tesco, Asda and Morrisons customers are being urged to use an "easy" trick when doing a food shop online.
The supermarkets are among a long list of retailers who offer a way to generate "extra cash" for deserving causes, without costing shoppers a penny extra. Buying things such as groceries and car insurance, or when booking hotels, can easily lead to a free donation.
Charity shopping platform easyfundraising wants more people to use its online service when buying items and goods as they can choose from thousands of charities and good causes.
