(37)The ‘Honour all Cards’ rule is a twofold obligation imposed by issuers and payment card schemes for payees to accept all the cards of the same brand, irrespective of the different costs of these cards (the ‘Honour all Products’ element) and irrespective of the individual issuing bank which has issued the card (the ‘Honour all Issuers’ element). It is in the interest of the consumer that for the same category of cards the payees cannot discriminate between issuers or cardholders, and payment card schemes and payment service providers can impose such an obligation on them. Therefore the ‘Honour all Issuers’ element of the ‘Honour all Cards’ rule is a justifiable rule within a payment card scheme, since it prevents payees from discriminating between individual banks which have issued a card. The ‘Honour all Products’ element is essentially a tying practice that has the effect of tying acceptance of low fee cards to the acceptance of high fee cards. A removal of the ‘Honour all Products’ element of the ‘Honour all Cards’ rule would allow merchants to limit the choice of payment cards they offer to low(er) cost payment cards only, which would also benefit consumers through reduced merchants' costs. Merchants accepting debit cards would then not be forced to accept credit cards, and those accepting credit cards would not be forced to accept commercial cards. However, to protect the consumer and the consumer's ability to use the payment cards as often as possible, merchants should be obliged to accept cards that are subject to the same regulated interchange fee only if issued within the same brand and of the same category (prepaid card, debit card or credit card). Such a limitation would also result in a more competitive environment for cards with interchange fees not regulated under this Regulation, as merchants would gain more negotiating power as regards the conditions under which they accept such cards. Those restrictions should be limited and considered acceptable only to enhance consumers' protection, giving to the consumers an adequate level of certainty about the fact that their payment cards will be accepted by the merchants.