The Price Indications (Method of Payment) Regulations 1991
These Regulations, which come into force on 28th February 1991, apply to any person who, in the course of business, gives to consumers (as defined in section 20(6) of the Consumer Protection Act 1987) indications of prices for goods (other than motor fuel), services, accommodation or facilities and who charges different prices for payment by different methods (for example, by cash or by credit card).