(1) The payment service providers involved are entitled to execute a payment transaction exclusively on the basis of the unique identifier stated by the payment service user. If a payment order is executed in accordance with this unique identifier, the payment order is deemed to have been executed properly with regard to the payee designated by the unique identifier.
(2) A unique identifier is a sequence of letters, numbers or symbols specified to the payment service user by the payment service provider and which the payment service user must provide in order to allow another payment service user or the payment account of that other payment service user to be unambiguously identified for a payment transaction.
(3) If a unique identifier stated by the payer cannot recognisably be attributed by the payer’s payment service provider to any payee or to any payment account, the service provider is obliged to inform the payer of this promptly, and where appropriate to return the payment amount to them.