World Library  
Flag as Inappropriate
Email this Article

Personal ID Number (CURP) (Mexico)

Article Id: WHEBN0026931952
Reproduction Date:

Title: Personal ID Number (CURP) (Mexico)  
Author: World Heritage Encyclopedia
Language: English
Subject: INSEE code
Publisher: World Heritage Encyclopedia

Personal ID Number (CURP) (Mexico)

The Clave Única de Registro de Población (translated into English as Unique Population Registry Code or else as Personal ID Code Number) (abbreviated CURP) is a unique identity code for both citizens and residents of Mexico. Each CURP code is a unique alphanumeric 18-character string intended to prevent duplicate entries.

How CURP codes are built

To understand how CURP codes are built, one must first understand Hispano American naming conventions. Full names in Spanish-speaking countries (including Mexican full names) consist of three elements:

  1. Given name(s);
  2. First surname: the father's first surname; and
  3. Second surname: the mother's first surname.

The CURP code is composed of 18 characters that are assigned as follows:

  • The first surname's initial and first inside vowel;
  • The second surname's initial (or the letter "X" if, like some foreign nationals, the person has no second surname);
  • The first given name's initial;
  • Date of birth (2 digits for year, 2 digits for month, and 2 digits for day);
  • A one-letter gender indicator (H for male (hombre in Spanish) or M for female (mujer in Spanish));
  • A two-letter code for the state where the person was born; for persons born abroad, the code NE (nacido en el extranjero) is used;
  • The first surname's second inside consonant;
  • The second surname's second inside consonant;
  • The first given name's second inside consonant; and
  • Two characters ranging from 1-9 for people born before 2000 or from A-Z for people born since 2000; these characters are generated by the National Population Registry to prevent identical entries.

For married women, only maiden names are used.

For example, the CURP code for a hypothetical person named Gloria Hernández García, a female, born on 27 April 1956 in the state of Veracruz, could be HEGG560427MVZRRL05.


Several exceptions to the above rules exist, including:


If any step in the above procedure leads to the letter "Ñ" appearing anywhere in the CURP, the "Ñ" is replaced by an "X".

Very common given names

When a person has two given names and the first given name is María, as is often the case for women in Mexico, or José, in the case of men, the first name will be overlooked and the fourth character will be taken from the second given name's initial. This is because the names María and José are very common and would generate many duplicates if used to generate the code.

For example, if the person were named María Fernanda Escamilla Arroyo, her CURP's first four characters would be ESAF because María does not count for the CURP's fourth character when a second given name is present.

Catalog of Inappropriate Words

To prevent words from forming that would be deemed palabras altisonantes (foul-sounding words, such as profanity or pejoratives) in the first four characters of the string, a Catalog of Inappropriate Words (Catálogo de Palabras Inconvenientes) lists many such possible combinations and provides replacements that usually entail changing the second letter, a vowel, into an "X".



Initially, a CURP card (cédula) was obtainable at CURP government offices, and also at the Civil Registry, ISSSTE, IMSS, and other government services; the document was printed on green paper at the time. Valid copies of existing CURPs can now be printed on plain paper by visiting an official website.


The CURP card is 5.4 cm wide and 8.6 cm long, fits in a wallet and may be laminated for preservation. The front of the card gives the CURP 18-character string, given names and surnames, plus the date of registration and a folio number. The back contains information referencing the document used as proof to originally assign the CURP code (if it was a birth certificate, folio number and issuing municipio are included), and a barcode.


On 23 October 1996, the Presidential Agreement for the Adoption and Use of the Population Registry Unique Code by the Federal Government (Acuerdo Presidencial para la adopción y uso por la Administración Pública Federal de la Clave Única de Registro de Población) was published in the Official Gazette of the Federation.

The Agreement provides assigning a CURP number to everyone living in Mexico and to Mexicans living abroad.

Currently the CURP is essential for tax filings, to keep records of companies, schools, membership in government-run health services, passport applications, and other government services.

The CURP number is now used in all Civil Registry individual records (birth and death certificates) and certified copies thereof.

Although primarily intended to substitute for a series of registration numbers (IMSS, RFC, IFE), the CURP has failed to replace any of these, which continue to use their own code-generation protocols. Nevertheless, the IFE voting card now contains both the IFE code and the CURP code.


Outside Mexico City, the Clave de Registro e Identidad Personal (Personal Registration and Identification Code) (CRIP) is used, in addition to CURP.

See also

External links

  • Consulta CURP, Official government website where an existing CURP may be consulted (in Spanish).
  • Instructivo normativo para la asignación de la Clave Única de Registro de Población
  • Calculadora CURP
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.