CURP

The Clave Única de Registro de Población. 18 characters that encode someone's name, birth date, sex and birth state.

Try it

CURPLOOA531113HTCPBN07Valid

Birth date: November 13, 1953
Sex: Male
State: Tabasco

Validate and parse

import { checkCurp, parseCurp, isValidCurp } from "mexico-utils";

parseCurp("LOOA531113HTCPBN07");
// {
//   curp: "LOOA531113HTCPBN07",
//   birthDate: "1953-11-13",
//   sex: "male",
//   state: { name: "Tabasco", curp: "TC", inegi: "27", iso: "MX-TAB", ... },
//   bornAbroad: false
// }

checkCurp looks at four things, in this order, and stops at the first one that fails:

Error	Meaning
`format`	Wrong length or characters in the wrong place
`date`	The birth date doesn't exist, like February 30
`state`	The two-letter state code isn't real
`check-digit`	The last digit doesn't match. Almost always a typo

sex is "male", "female" or "nonbinary" (RENAPO added X in 2022). People born abroad have state: null and bornAbroad: true.

Generate

import { generateCurp } from "mexico-utils";

generateCurp({
  name: "Enrique",
  firstLastName: "Peña",
  secondLastName: "Nieto",
  birthDate: "1966-07-20",
  sex: "male",
  state: "Estado de México",
});
// "PXNE660720HMCXTN06"

It follows RENAPO's rules:

Particles like "de", "la", "del" or "van" are skipped, so "de la Cruz" uses "Cruz".
"María" and "José" give way to the second name when there is one.
Ñ becomes X.
When the first four letters spell a rude word, the second one becomes X. That's why Peña Nieto's CURP starts with PXNE.
state takes a name, any of its codes, or "NE" for people born abroad. birthDate takes YYYY-MM-DD or a Date.

Try it in the playground, where you can see where each character comes from.

The 17th character is set by RENAPO to tell apart people who'd otherwise get the same CURP. generateCurp uses 0 for people born before 2000 and A after, which is what nearly everyone gets. A few people will have different last two characters, so use it to pre-fill or double-check a form, not as the source of truth.