Some stores such as Tesco, ASDA, Morrisons and Ocado only donate to first time customers when shopping for groceries. However Iceland, Waitrose and Sainsbury's do continue to donate on each shop.
Most of our stores do have a flat rate percentage across the board, but you can expect different rates for supermarkets, department stores, electrical stores, subscription services and catalogue websites.
These are listed on the store page and shopping bar under 'see all donation rates and terms'.