CURP Number in Mexico: What It Is and How to Get It

The CURP number in Mexico is an 18-character alphanumeric code that identifies every Mexican citizen and legal resident, roughly the way a Social Security number identifies a person in the United States. It is issued free by the National Population Registry (RENAPO), stays with you for life, and encodes your name initials, date of birth, gender, and place of birth directly into the code itself.

Most people never apply for a CURP in the ordinary sense. Mexican citizens get one when their birth is registered, and foreign residents get one with their residency card. What you usually need to do is find yours, download it as a PDF, and correct it if something is wrong.

How to Get a CURP

If You Were Born in Mexico

A CURP is typically assigned automatically when parents register a birth at a Civil Registry office, so most Mexican citizens already have one without having filed anything. If yours was never assigned, or you cannot locate it, go to your local Civil Registry office with your birth certificate and an official photo ID.

If You Are a Foreign Resident

Foreigners who hold a Temporary or Permanent Resident Card issued by the National Institute of Migration (INM) receive a CURP automatically as part of the residency process. The 18-character code is printed on the residency card. No separate application is needed in most cases.

If your CURP was not printed on your card, or the record cannot be found online, RENAPO directs foreign residents to their local INM office. Bring your original residency card, your birth certificate, and a valid passport. A foreign-language birth certificate may need to be translated into Spanish by a certified translator (a perito traductor) and, depending on your country, apostilled or legalized through the appropriate consular channel.

Children Born in Mexico to Foreign Parents

A child born on Mexican soil receives a CURP when the birth is registered at a Civil Registry office, regardless of the parents’ nationality. Parents should bring the hospital birth record and their own identification to complete the registration.

Looking Up and Downloading Your CURP

The official portal at gob.mx/curp lets you look up your CURP and download it as a PDF, free, as many times as you want.1gob.mx. CURP Tramites Two search methods are available:

  • By the 18-character code, if you already know it.
  • By personal data: full name (first name, paternal surname, maternal surname), date of birth, gender, and state of birth. If you were born abroad, select “Nacido en el extranjero” from the state dropdown.1gob.mx. CURP Tramites

After a security check, the site generates a PDF. That printout is accepted for most administrative purposes in Mexico, from opening bank accounts to enrolling in school.

What the 18 Characters Mean

The code follows a fixed structure, and reading it is straightforward once you know the segments:

  • Characters 1–4: letters from your names. The first two come from the initial letter and first internal vowel of your paternal surname, the third from the initial of your maternal surname, and the fourth from the initial of your first name.
  • Characters 5–10: your date of birth in YYMMDD format.
  • Character 11: gender. “H” for male, “M” for female. The gob.mx search form also lists “No binario” as an option.1gob.mx. CURP Tramites
  • Characters 12–13: a two-letter code for your state of birth, or “NE” (Nacido en el Extranjero) if you were born abroad.1gob.mx. CURP Tramites
  • Characters 14–16: the first internal consonant of each of your three names.2Oracle Help Center. Person National Identifiers for Mexico
  • Character 17: a “homoclave” letter assigned by RENAPO to prevent duplicates.
  • Character 18: a check digit. People born before 2000 get a number (0–9); those born in 2000 or later get a letter (A–Z).

What You Use a CURP For

The CURP shows up in nearly every interaction with Mexican bureaucracy:

  • Employment. Employers need your CURP to register you with social security (IMSS) and to run payroll.
  • Social security and healthcare. Your CURP is required to obtain your IMSS social security number (NSS), which unlocks public healthcare, disability benefits, retirement savings, and daycare.3Consulado de México en San Bernardino. Incorporacion al Seguro Social desde el Extranjero
  • Tax registration. The CURP is a prerequisite for the RFC, Mexico’s taxpayer ID issued by SAT.
  • Banking. Opening a Mexican bank account requires a CURP.
  • Education. Schools at every level require it for enrollment.
  • Real estate. Buying property in Mexico requires an RFC, which in turn requires a CURP. Foreigners sometimes discover this late in a purchase and lose time.
  • Government documents. Applying for a Mexican passport or driver’s license requires presenting your CURP.

Fixing Errors or Duplicates

If your CURP shows the wrong name, date of birth, gender, or birthplace, or if the system has assigned you more than one CURP, there are three ways to fix it:

  • In person. Visit any CURP service module or Civil Registry office with your birth certificate (or naturalization certificate), an official photo ID such as a passport or INE voter card, and your residency card if you are a foreigner.
  • By email. Write to tramitescurp@segob.gob.mx describing the error. Attach a photo or scan of your birth certificate and ID, and include a phone number for callback.
  • By phone. Call 55 5128 0000 or the toll-free line 800 911 1111, Monday through Friday, 8 a.m. to 6 p.m.

Get errors corrected before you need the CURP for anything important. IMSS, for example, will not process a social security registration when the CURP data does not match; the system rejects the application until the mismatch is resolved.3Consulado de México en San Bernardino. Incorporacion al Seguro Social desde el Extranjero

The Biometric CURP

Mexico is converting the CURP into a biometric credential. A law signed in July 2025 amended the General Population Law to make a biometric version mandatory, and pilot programs launched that year in states including Veracruz, Mexico City, and the State of Mexico. The biometric CURP collects a facial scan, fingerprints, and an iris scan.

As of February 2026, the biometric CURP is officially mandatory, and both public agencies and private businesses are required to accept it as valid identification for healthcare, social programs, pensions, financial services, school enrollment, and other procedures. Registration is available at Civil Registry offices and RENAPO offices, with the rollout continuing in phases through 2026 as more locations are equipped to capture biometric data.

For foreign residents, RENAPO still directs CURP-related matters to the local INM office. Whether immigration offices will collect additional biometrics beyond what is already gathered during the residency card process has not been clarified.

Alongside the biometric CURP, the government launched Llave MX, a free digital authentication platform linked to your CURP. Setting up an account requires your CURP, a mobile phone number, an email address, and a password, and takes about five minutes. You can optionally share fingerprints and a photo to create a “verified” account with higher-level access.4gob.mx. Llave MX