A power of attorney signed before a notary in Spain does not automatically work in Mexico, and one signed in Mexico does not automatically work in Spain. The form of a power of attorney is governed by the law of the country where it is granted, and that determines which route to use depending on where it will be exercised.
The starting rule: the country of execution decides the form
The Spanish Civil Code provides, in article 11, paragraph 1, that the forms and formalities of contracts, wills and other legal acts are governed by the law of the country in which they are executed. A power of attorney being properly granted where it was signed does not mean the authority of the other country will accept it as it stands.
A second rule applies to representation itself: in the absence of an express submission, voluntary representation is governed by the law of the country where the powers conferred are exercised (article 10, paragraph 11, of the same Code). There is also a mirror rule: contracts, wills and other legal acts authorised by Spanish diplomatic or consular officers abroad are governed by Spanish law (article 11, paragraph 3).
For a power of attorney to take effect in Mexico
When the power of attorney is meant for use in Mexico, there are two routes.
The first is the Mexican consulate in Spain. Heads of consular offices exercise notarial functions in acts and contracts entered into abroad that must be carried out in Mexican territory, and their authority carries the same legal weight throughout the Republic as that of notaries in Mexico City (Ley del Servicio Exterior Mexicano, article 44, section IV). That authority has a closed list: the Regulation to that Law specifies that, in exercising their notarial functions, heads of consular offices may attest, authenticate, formalise and revoke mandate and power of attorney contracts, public open wills, acts of renunciation of an inheritance and authorisations granted by those exercising parental authority or guardianship over minors or persons lacking capacity, provided the act takes place within their consular district and is intended to take effect in Mexico (article 87).
The second route is a notary in Spain. In that case, for Mexican authorities the resulting document is a foreign public document: for it to be given effect in Mexico, the Código Federal de Procedimientos Civiles requires it to be presented legalised (apostilled, where the country of origin is party to the Hague Convention abolishing that requirement) by the competent authorities (article 546).
The consular route avoids the apostille step, but it only covers the acts on the closed list of article 87. Outside that list, the notarial route in Spain followed by an apostille is the one that applies.
For a power of attorney to take effect in Spain
When the power of attorney is granted in Mexico to be used in Spain, the same two rules of the Spanish Civil Code cited above apply: the form is governed by the country where it is granted (Mexico, in that case), and the powers are exercised according to the law of the country where they will be exercised, unless an express submission says otherwise. A power of attorney granted before a Mexican notary for use in Spain follows, as a result, the same path as any Mexican public document intended to take effect on Spanish territory: it needs the corresponding apostille before being presented to the relevant Spanish authority or registry.
The detail that most often stops the process
Not every kind of power of attorney covers every kind of act, and confusing one kind with another is among the most common reasons for rejection. The Código Civil Federal distinguishes three kinds of general power of attorney in its article 2554: for litigation and collection (claiming and collecting on behalf of someone else), for acts of administration (preserving and managing assets), and for acts of ownership (disposing of them: selling, encumbering, donating). It is enough for the power of attorney to state the relevant capacity for the holder to have, without more, all the powers of that kind. If those powers are to be limited, the limitations must be stated expressly, or the power of attorney will be a special one.
A power of attorney granted "for administration" does not, therefore, authorise a sale. Before granting any power of attorney, it is worth reviewing exactly which act it needs to accomplish and drafting it under that precise kind.
Common mistakes
- Assuming a power of attorney signed before a notary works the same way in the other country.
- Going to the consulate for an act outside the closed list of its notarial functions.
- Granting a power of administration when the act needed is one of ownership (selling, encumbering, donating).
- Presenting a Spanish notarial power of attorney in Mexico without the corresponding apostille.
- Assuming a power of attorney has indefinite validity without checking what the document itself or the receiving authority requires.
What we do
We review where the power of attorney needs to take effect, which specific powers are required and which route (consular or notarial, with apostille) fits the case. We prepare the corresponding documentary work. Set out your case in writing: we reply within 24 to 48 working hours and state the fixed fee in advance.
Sources
- Spanish Civil Code, articles 10.11, 11.1 and 11.3 (consolidated text, consulted in October 2026)
- Ley del Servicio Exterior Mexicano, article 44, section IV (current text, last amended in the Official Gazette of the Federation on 19 April 2018, consulted in October 2026)
- Regulation to the Ley del Servicio Exterior Mexicano, article 87 (current text, last amended in the Official Gazette of the Federation on 27 May 2025, consulted in October 2026)
- Código Federal de Procedimientos Civiles, article 546 (current text, last amended in the Official Gazette of the Federation on 7 June 2021, consulted in October 2026)
- Código Civil Federal, article 2554 (current text, last amended in the Official Gazette of the Federation on 14 November 2025, consulted in October 2026)