Article 12 of Directive 2002/20/EC on the authorisation of electronic communications networks and services (Authorisation Directive) must be interpreted as not precluding the legislation of a Member State, such as the legislation at issue in the main proceedings, under which operators providing mobile telephony services are liable to pay ‘excise' duty, calculated as a percentage of the charges paid to them by the users of those services, provided the trigger for that duty is not linked to the general authorisation procedure for access to the electronic communications services market but to the use of mobile telephony services provided by the operators and the duty is ultimately borne by the user of those services, which is a matter for the national court to verify.