As I am sure most people know, from 13th Jan, you cannot be charged a surcharge for paying for something by card. This even applies to small corner shops. It is because of the The Payment Services Regulations 2017
What does that mean exactly?
Shops can still operate a minimum spend. Whereas before they may have said a charge only for transactions under, say £5, they may instead simply refuse to take cards for purchases under £5 for example. This creates more inconvenience for shoppers. This may however be a matter of the contract they have with the card processing company which may require the shop to treat cards the same as cash. You are not a party to that contract though, and it is probably not a trading standards issue either.
Yes the shop keeper pays to handle cards. The card processing companies still charge the shops for handling cards.
They may put up prices. This was commented by someone as a "way around the new law", which I find odd. The law is simply to encourage a more easily trackable cashless society, not to save anyone money (the cynicism is strong in me today). If a business has increased costs then obviously increasing prices is likely to happen. The shops have costs to process cards, and the use of cards is likely to increase because of this change. Obviously increased prices is a logical outcome - it is what you would expect, of course, and not a "way around" the law, sorry.
No, they cannot do a "discount for cash". This would be the same as a surcharge for paying by card.
No, they don't have to take cards, or take all types of card. It is generally up to the shop keeper to decide if they take cards and which cards. This may however be a matter of the contract they have with the card processing company. At present many shops do not take Amex due to high costs, it is possible some shops will no longer accept credit cards but only debit cards for the same reasons.
Yes, they can charge admin or booking fees. As long as they are not charging for payment by card, there can be other fees, e.g. on-line cinema ticket sales may have a "booking fee" still.
Yes it applies to Apple Pay even though it is not an actual "card". Anything that allows a card payment to be instigated, so probably even applies to using PayPal.
This is not world wide. This is an EU based change, so on-line shops selling things and changing cards in other countries may not have the same rules.
If they try to charge a fee, report to local trading standards. Card processing companies are telling their clients this, so they should know!