At the SAT office:
If you are a natural person or taxpayer residing abroad who carries out maquila operations through a company with an IMMEX program under the shelter modality, obtain your Password after an appointment registered on the SAT Portal:
https://citas.sat.gob.mx/citasat/home.aspx
In the case of legal entities, the original and a copy of the power of attorney must be presented that certify the personality of the legal representative and have the e.signature.
What is the e.signature?
The e.signature or Advanced Electronic Signature of the SAT is equivalent to the autograph signature but also includes aspects that guarantee authenticity, integrity, technological neutrality, non-repudiation and confidentiality.
This, according to Prodecon, is relevant because the e.signature protected by a current certificate replaces the autograph signature of the signatory in the digital documentsguaranteeing the integrity of those, for which it will produce the same effects that the laws grant to documents with an autograph signature and will have the same probative value.
Thus, the e.firma, in addition to allowing access to different applications and services of the SAT, is used to sign electronic documents, contracts, requests for procedures and government services.
The e.signature is created from your personal, biometric data and is made up of three elements: cer. file, .key and a password.