Mexico gives U.S. litigants two treaty routes. It joined the Hague Service Convention in 2000, with its Central Authority at the Ministry of Foreign Affairs (Secretaría de Relaciones Exteriores, through its Directorate-General of Legal Affairs), and it is also a treaty partner of the United States under the Inter-American Convention on Letters Rogatory and its Additional Protocol. Mexico has objected to all of the alternative methods in Article 10, so service by mail or by a private agent isn't valid Convention service.
Once the Ministry accepts a request, it forwards it to the competent Mexican court, where a court officer (actuario) delivers the documents and the certificate is returned through the Central Authority. Everything must be in Spanish, and Mexican addresses need to be complete: street and number, colonia, municipality or alcaldía, state and postal code. An incomplete address is one of the most common reasons a request comes back unserved.