In a business sense, credit notes are invoices which you issue to us and which we must pay, even if we actually issue them ourselves. From the point of view of commerce and tax laws, it is not necessary for you to receive a credit note from us by post or even in the form of an electronically signed transmission. The requirements are satisfied if you can verify this voucher in your customer account or as a printed-out PDF in order to legitimize your receipt of the payment.