The sphere of activity is specified in Article 3 of the Ministerial Order of 3 April 1995 (BOE  of 7 April) on the use of electronic, telematic and computer media for registration of companies, affiliation, acquisition and termination of active contributor status and changes of details for workers, contributions and collection within the scope of the Social Security.

This Ministerial Order states that the RED System will include companies, groups of companies and other parties who are liable to make contributions, as well as members of professionals associations and those persons who in their occupational activity must fill in or submit documents regarding the activities described in this Order and who must represent companies or individuals who are liable to make contributions and in whose name they are acting, under the terms provided for by law.

Following the publication of TIN Order 2777/2010 of 29 October, the TGSS , as of 1 January 2011, has extended the compulsory nature of effective incorporation into the RED System to all companies in the General Scheme, irrespective of the number of workers with active contributor status, as well as to companies included in the other schemes which have over 10 workers with active contributor status. It also provides for the compulsory nature of payment through the available methods therein for all companies required to join or which were voluntarily using this system, except in those cases in which the RED System, for technical reasons, is unable to issue the applicable contribution payment receipt.

This authorisation is granted to the aforementioned groups, under the terms of the following schemes:

• General Scheme, (including: the Special Scheme for Artists, the Special System for Fruits, Vegetables and Canned Vegetables, the Special System for the Handling and Packaging of Fresh Tomatoes, and the Special Agricultural System (actual days worked)).
  
  
• Special Schemes for Sea Workers (Employed Workers) and Coal Mining.