I don't think we can selectively reject them, it's not anything I've looked into though so not certain about that.

Although we are a B2B business, most of our card transactions are from business owners personal cards so it's not really an issue. We occasionally monitor the split and if it became significant we'd need to look at addressing it, probably by increasing prices for those customers.

In Denmark many retailers pass on the charge for business cards. For example it's often printed on the bottom of a restaurant menu.