[chrisseaton]

> Sometimes, this results in a small charge for using a credit card.

That's not the way it's been for years - it became illegal in the UK to do this a while ago.

[jsjohnst]

> That's not the way it's been for years

If it’s a Visa or MC backed card, it’s always been against their merchant policies to surcharge a CC and merchants can lose their ability to process cards if they do. It definitely hasn’t stopped merchants from doing it though (in the US mainly, but have seen it elsewhere too).