(21)In order to allow account information service providers, payment initiation service providers, and payment service providers issuing card-based payment instruments to develop their technical solutions, the technical specification of the interface should be adequately documented and made publicly available. Moreover, the account servicing payment service provider should offer a facility enabling the payment service providers to test the technical solutions at least 6 months prior to the application date of these regulatory standards or, if the launch takes place after the application date of these standards, prior to the date on which the interface will be launched to the market. To ensure the interoperability of different technological communication solutions, the interface should use standards of communication which are developed by international or European standardisation organisations.