I'll do one better
www.mastercard.com/us/merchant/pdf/BM-Entire_Manual_public.pdf

5.11.3 Minimum/Maximum Transaction Amount Prohibited
A Merchant must not require, or indicate that it requires, a minimum or
maximum Transaction amount to accept a valid and properly presented Card.

They're allowed to charge you to use your card, however the charge "must bear a reasonable relationship to the Merchant’s cost of accepting Cards". (5.11.2 under Europe Region Rules).
(chuckle_h0und You furnish the pictures, I'll furnish the war, Mon 14 Feb 2011, 14:54, 1 reply)

Do Mastercard provide all card readers?

( WormuIus, Mon 14 Feb 2011, 18:15, closed)

They don't need to
They don't supply any equipment, the banks do. That equipment processes Mastercard, Visa and Switch (and for an additional fee, Amex).

If they accept Mastercard, they need to abide by their rules. If the equipment allows them to process the transaction, they can't refuse one card company:

5.11.1 Discrimination
A Merchant must not engage in any acceptance practice that discriminates against or discourages the use of a Card in favor of any other acceptance brand.

they're unable to refuse to accept Mastercard if the machinery can process the transaction.

All it boils down to is that MC and Visa have retailers over a barrel, but as I've said I have no desire to use this except as a way to get back at a company that has warranted it.
(chuckle_h0und You furnish the pictures, I'll furnish the war, Mon 14 Feb 2011, 21:30, closed)

top fecking post!
good effort, well impressed!
( blaireau69 , the Cumbrian Travis Bickle., Mon 14 Feb 2011, 21:58, closed)

Wait a sec...
Does this mean by quoting Merchant Agreements at the people commenting, I've technically scored a little victory?
(chuckle_h0und You furnish the pictures, I'll furnish the war, Mon 14 Feb 2011, 22:10, closed)

i think so, considering you expended the effort to hunt them out first...
is that a bad thing?
( blaireau69 , the Cumbrian Travis Bickle., Mon 14 Feb 2011, 22:28, closed)

It might be...
I was supposed to be working at the time.
(chuckle_h0und You furnish the pictures, I'll furnish the war, Tue 15 Feb 2011, 10:03, closed)