PUI Law glossary: every term, explained precisely
The Single Identity Platform uses technical and legal vocabulary that confuses many lodging owners. This glossary defines each key PUI Law term precisely and in clear language: from PUI itself and the LGMDFP to the UMA, CURP, e.firma, LlaveMX and SNIP.
The law and its foundations
Where the obligation comes from and how it’s penalized.
PUI
Single Identity Platform (Plataforma Única de Identidad). The federal system every lodging in Mexico must connect to in order to register guest identity and allow queries that help locate missing persons.
LGMDFP
General Law on Enforced Disappearance of Persons, Disappearance Committed by Individuals and the National Search System. The federal law that creates the PUI obligation for lodgings.
Article 12 Bis
The LGMDFP article that sets the obligation: every lodging establishment must register guest identity and connect to the Single Identity Platform.
Article 43 Bis
The LGMDFP article that sets the penalty for non-compliance: a fine of 10,000 to 20,000 UMA per infraction, roughly $1.17 to $2.35 million pesos.
UMA
Unit of Measure and Update (Unidad de Medida y Actualización). The reference value used to calculate fines. Its 2026 daily value is $117.31 pesos.
Guest data and identity
What is captured from each person who lodges.
CURP
Unique Population Registry Code. An 18-character code identifying each person in Mexico; one of the core data points the PUI requires for a Mexican guest.
FMM
Multiple Migratory Form (Forma Migratoria Múltiple). The document evidencing a foreigner’s legal entry to Mexico; together with the passport and nationality, it’s what’s recorded for a foreign guest.
Registry / guest book
The guest record every lodging must keep and retain: the identity of each person lodged, available to answer an authority’s query.
Digital identity and technical connection
The credentials and mechanisms to connect to the federal platform.
e.firma
The SAT’s advanced electronic signature (formerly FIEL). A digital credential that securely identifies a person or company to the government; used to register the lodging on the PUI portal.
LlaveMX
Mexico’s government digital access key. A single digital identity letting individuals and companies authenticate on official platforms, including the PUI’s.
Endpoint / query URL
The secure address (URL) each lodging registers to receive the authority’s queries, protected with mechanisms such as JWT and TLS per the Technical Manual.
Query model
The PUI’s operating method: the authority asks about a specific person when it’s searching, rather than monitoring all guests live.
Institutions and official publications
The bodies involved and where the rule is published.
SNIP
National Persons Information System (Sistema Nacional de Información de Personas). The information infrastructure tied to the search; its Operation Manual, still pending, will define full federal interconnection.
RENAPO
National Population Registry. The authority that administers the CURP and the population’s identity data in Mexico.
CNB
National Search Commission (Comisión Nacional de Búsqueda). The body charged with coordinating the search for missing persons, a beneficiary of the PUI’s information.
ATDT
Agency for Digital Transformation and Telecommunications. A federal entity tied to the government’s digital infrastructure, including digital identity.
DOF
Official Gazette of the Federation. Where official rules are published: the PUI Guidelines (November 27, 2025) and the Technical Manual (January 23, 2026).