The MUX unified registration service is a service that the AOC makes available to Catalan public administrations that allows the integration of the AOC's services with the general register of entries and exits specific to each entity.

With this integration, entries of entry or exit entries generated by the AOC services are made directly in the body's general register instead of in the EACAT auxiliary electronic register. Rules can be defined that allow different registrations to be settled depending on the request parameters that are established.