In the case of a law firm organised as a "Professional Society", the majority of the members of the administrative bodies, as well as the CEOs, must be locally-licensed professionals. However, professionals can establish within the general regime, as corporations or limited societies for activities apart from those for which registration is required. Restrictions concern domestic law and representation before domestic courts or judicial bodies. Advice on home-country law, international law and third-country law is not regulated in Spain. In order to be registered with the Spanish bar, the applicant must have Spanish, EU or EEA nationality, except as provided in international treaties or conventions. Third-country nationals may apply for dispensation from the Spanish nationality requirement by request to the Ministry of Justice.
"Article 11.
Membership in a Bar Association is mandatory for the practice of law, except in cases expressly determined by the Law or by this General Statute. It will be enough to join a single College, which will be that of the sole or main professional domicile, to practice throughout the territory of the State.
[...]
Article 13.
1. Joining a Bar Association will require the following requirements:
a) Have Spanish nationality or a member state of the European Union or the agreement on the European Economic Area of ​​May 2, 1992, except as provided in international treaties or conventions or legal dispensation.
[...]
Article 28.
1. Lawyers may practice law collectively, through their grouping under any of the legal forms in law, including commercial companies.
2. The group must have as its exclusive object the professional practice of law and be made up exclusively of practicing lawyers, without limitation of number. You may not share premises or services with incompatible professionals, if this affects the safeguarding of professional secrecy. Both the capital and the political and economic rights must be attributed only to the lawyers who make up the collective law firm.
[...]
Article 29.
1. Lawyers may associate in a multiprofessional collaboration regime with other non-incompatible liberal professionals, without limitation of number and without affecting their full capacity to exercise the profession before any jurisdiction and Court, using any form that is lawful in law, including commercial companies, provided that the following conditions are met:
a) The purpose of the grouping is to provide specific joint services, including specific legal services that complement those of the other professions.
b) That the activity to be carried out does not affect the correct exercise of the legal profession by the lawyer members.
c) That the conditions established in the previous article are met in what affects the practice of law, except as expressed under section 2 of the same, which will not be applicable, or in section 4 of which only the obligation to to record the condition of member of the multiprofessional group in the actions that are carried out and minutes that are issued in their field. [...]" (Royal Decree approving the General Statute of Spanish Lawyers (658/2001, of June 22), last amended on 13 October 2003, Articles 11, 13, 28 and 29 [google translation])
--------------------
"Article 4. Composition.
1. They are professional partners:
a) Natural persons who meet the requirements for the exercise of the professional activity that constitutes the corporate purpose and who exercise it within it.
b) Professional societies duly registered in the respective Professional Associations that, constituted in accordance with the provisions of this Law, participate in another professional society.
2. As a minimum, the majority of the capital and voting rights, or the majority of the corporate assets and the number of partners in non-capitalist companies, must belong to professional partners.
3. Likewise, at least half plus one of the members of the administrative bodies, where appropriate, of the professional societies, must be professional partners. If the management body is unipersonal, or if there are CEOs, these functions must necessarily be performed by a professional partner. In any case, the decisions of the collegiate administrative bodies will require the favorable vote of the majority of professional partners, regardless of the number of concurrent members.[...]" (Law on professional companies (2/2007, of March 15), last amended on 23 December 2009, Article 4 [google translation])
--------------------
"Article 1. Object and purpose of the law.
1. The purpose of this law is to regulate the conditions for obtaining the professional title of lawyer and the professional title of attorney of the courts, as collaborators in the exercise of the fundamental right to effective judicial protection, in order to guarantee the access of the citizens to quality advice, legal defense and technical representation.
2. Obtaining the professional title of lawyer in the manner determined by this law is necessary for the performance of legal assistance in those judicial and extrajudicial processes in which current regulations impose or authorize the intervention of a lawyer, and, in any case , to provide legal assistance or legal advice using the name of lawyer; all this without prejudice to the fulfillment of any other requirements demanded by the current regulations for the practice of law.
3. Obtaining the professional title of attorney of the courts in the manner determined by this law is necessary to perform the legal representation of the parties in judicial processes as attorney, performing the acts of communication to the parties and those other acts of cooperation with the Administration of Justice that the law authorizes, as well as to use the name of attorney of the courts, without prejudice to the fulfillment of any other requirements demanded by the current regulations for the exercise of the prosecution.
4. Obtaining the professional titles of lawyer or solicitor will be an essential requirement for membership in the corresponding professional associations.[...]" (Law on access to the professions of Lawyer and Court Attorney (34/2006, of October 30), last amended on 21 November 2014, Article 1 [google translation])
Royal Decree approving the General Statute of Spanish Lawyers (658/2001, of June 22), last amended on 13 October 2003, Articles 11, 13, 28 and 29 
Law on professional companies (2/2007, of March 15), last amended on 23 December 2009, Article 4
Law on access to the professions of Lawyer and Court Attorney (34/2006, of October 30), last amended on 21 November 2014, Article 1 
[<a href="https://www.boe.es/buscar/act.php?id=BOE-A-2001-13270&tn=1&p=20031013">Decree</a>],[<a href="https://www.boe.es/buscar/act.php?id=BOE-A-2007-5584">Law</a>],[<a href="https://www.boe.es/buscar/act.php?id=BOE-A-2006-18870">Law</a>],[<a href="https://www.abogacia.es/conocenos/consejo-general/ejercicio-de-la-abogacia/ejercicio-de-la-abogacia-en-espana-por-graduados-o-abogados-extranjeros/">Guide</a>]