-
gift aid / write off tax donations.
I don't know anything about the tax affairs of the companies that use pennies.org.uk, but I do know that 100% of the donations go to the charity, with nothing being passed to either the "host" retailer or pennies themselves. The latter are a not-for profit that are 100 percent funded by philanthropic donations. Or at least they were when I worked there. I haven't kept up to date, but am sure that the information is freely accessible on their website.
I should note that I worked there on a voluntary pro bono basis, as did a lot of other (some very senior) consultants there.
I used to do some consulting work for pennies.org that is the charity that delivers this service for a lot of online and card retailers, matched to charities. The basic premise is to replace the collecting pots that you used to put your change in, back when cash was thing.
lovely people and a really nice ethos.