Cashback where it started

WestonDave

There's a 1.5% charge because that is what the card system provider charges the merchant - that frankly is pretty good as it can be as high as 3% of the gross value of the transaction (so including the VAT if relevant). Debit cards aren't charged in the same way - normally 20p or so per transaction - this is because on a debit transaction the card system doesn't allow for chargebacks, and its the risk of covering these costs which create the % charge.

The merchants attitude to passing on these charges will often depend on whether they are typical in that business. So a supermarket won't because pretty much everyone pays by some kind of card so they might as well just roll it up into their markup on goods. On the other hand a business which largely gets paid by direct debit might think that if there are one or two awkward types that want to be special, then they can have a special charge!