🪪 CURP Status

The CURP validation report verifies Mexico’s national identification number (Clave Única de Registro de Población) and retrieves associated personal data from the official RENAPO database.

Overview

CURP validation is the foundation of identity verification in Mexico. This report validates the document ID format, confirms its existence in the national registry, and retrieves associated personal information for cross-verification with other reports.

Input Requirements

Required Fields

Field	Type	Description	Example
`document_id`	string	18-character CURP code	`ABCD123456EFGHIJ78`
`city_locode`	string	UN LOCODE of the city	`MX MEX`

Optional Fields

Field	Type	Description	Default
`full_name`	string	Expected full name for verification	`null`
`date_of_birth`	string	Expected date of birth (YYYY-MM-DD)	`null`

CURP Format Specification

The CURP follows a specific 18-character format:

ABCD123456EFGHIJ78

Character Breakdown

Position	Characters	Description	Example
1-2	Letters	First surname initial + vowel	`AB`
3-4	Letters	Second surname + first name initials	`CD`
5-10	Numbers	Birth date (YYMMDD)	`123456`
11	Letter	Gender (H=Male, M=Female)	`E`
12-13	Letters	Birth state code	`FG`
14-16	Letters	Internal consonants	`HIJ`
17	Number/Letter	Homonym differentiator	`7`
18	Number	Check digit	`8`

Data Source

Registry: Registro Nacional de Población (RENAPO) Authority: Secretaría de Gobernación (SEGOB) Coverage: All Mexican citizens and legal residents Update Frequency: Real-time

Output Schema

Successful Validation

{
  "id": "beb8716f-34cc-4582-aafa-ef011b1cc6f5",
  "reports": {
    "curp": {
      "state": "COMPLETED",
      "created_at": "2021-03-30T03:18:31.242613",
      "updated_at": "2021-03-30T03:18:41.915065",
      "outcome": "PASSED",
      "details": {
        "curp": "ABCD123456EFGHIJ78",
        "full_name": "JUAN MIGUEL DOE ROE",
        "forenames": "JUAN MIGUEL",
        "surname": "DOE",
        "mothers_surname": "ROE",
        "gender": "M",
        "dob": "01-01-1900",
        "state_born": "VERACRUZ",
        "validation": {
          "format_valid": true,
          "check_digit_valid": true,
          "registry_found": true
        }
      }
    }
  }
}

Invalid CURP Response

{
  "id": "beb8716f-34cc-4582-aafa-ef011b1cc6f5",
  "reports": {
    "curp": {
      "state": "COMPLETED",
      "created_at": "2021-03-30T03:18:31.242613",
      "updated_at": "2021-03-30T03:18:41.915065",
      "outcome": "FAILED",
      "details": {
        "curp": "INVALID123456789012",
        "validation": {
          "format_valid": false,
          "check_digit_valid": false,
          "registry_found": false,
          "errors": [
            "Invalid CURP format",
            "Check digit mismatch",
            "Not found in RENAPO registry"
          ]
        }
      }
    }
  }
}

Validation Logic

Format Validation

Length Check: Must be exactly 18 characters
Character Pattern: Letters and numbers in correct positions
Date Validation: Birth date must be valid calendar date
State Code: Must be valid Mexican state code
Gender Code: Must be ‘H’ (Hombre) or ‘M’ (Mujer)

Check Digit Algorithm

The 18th character is calculated using a specific algorithm:

// Simplified check digit calculation
function calculateCheckDigit(curp17chars) {
  const weights = [18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2];
  const charValues = {
    '0':0,'1':1,'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9,
    'A':10,'B':11,'C':12,'D':13,'E':14,'F':15,'G':16,'H':17,'I':18,
    'J':19,'K':20,'L':21,'M':22,'N':23,'Ñ':24,'O':25,'P':26,'Q':27,
    'R':28,'S':29,'T':30,'U':31,'V':32,'W':33,'X':34,'Y':35,'Z':36
  };

  let sum = 0;
  for (let i = 0; i < 17; i++) {
    sum += charValues[curp17chars[i]] * weights[i];
  }

  const remainder = sum % 10;
  return remainder === 0 ? 0 : 10 - remainder;
}

CURP validation enables and validates other Mexico reports:

Name Check Report

Validates provided full_name against RENAPO data:

{
  "name_check": {
    "outcome": "PASSED",
    "details": {
      "score": 1.0,
      "full_name": "JUAN MIGUEL DOE ROE",
      "name_fragment_check": false,
      "name_score_min": 1.0
    }
  }
}

DOB Check Report

Validates provided date_of_birth against RENAPO data:

{
  "dob_check": {
    "outcome": "PASSED",
    "details": {
      "provided_dob": "1900-01-01",
      "registry_dob": "01-01-1900",
      "match": true
    }
  }
}

API Integration

Create Person with CURP Validation

curl -X POST "https://api.emptor.io/v3/mx/persons" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "document_id": "ABCD123456EFGHIJ78",
    "city_locode": "MX MEX",
    "pipeline": {
      "name": "basic_id_check"
    }
  }'

Get CURP Report Details

curl -X GET "https://api.emptor.io/v3/mx/details/{person_id}/curp" \
  -H "X-Api-Key: YOUR_API_KEY"

Error Handling

Common Validation Errors

Error Type	Description	Resolution
`INVALID_FORMAT`	CURP doesn’t match 18-character pattern	Verify CURP format and characters
`INVALID_CHECK_DIGIT`	Check digit calculation fails	Verify CURP was entered correctly
`INVALID_DATE`	Birth date in CURP is invalid	Check date components (YYMMDD)
`INVALID_STATE_CODE`	State code not recognized	Verify state code is valid Mexican state
`NOT_FOUND_IN_REGISTRY`	CURP not found in RENAPO	Verify CURP exists and is active
`REGISTRY_TIMEOUT`	RENAPO database timeout	Retry after a few minutes

Best Practices

Input Validation: Always validate CURP format before API calls
Error Handling: Implement proper error handling for all validation failures
Retry Logic: Implement exponential backoff for registry timeouts
Data Privacy: Handle personal data according to Mexican privacy laws

Business Logic

When to Use CURP Validation

Identity Verification: Primary identity check for Mexican individuals
Document Verification: Validate government-issued documents
KYC Compliance: Know Your Customer requirements
Employment Screening: Verify candidate identity
Financial Services: Account opening and verification

Integration Patterns

Basic Identity Check

CURP → Name Check → DOB Check

Standard Background Check

CURP → Name Check → DOB Check → Criminal Records → Tax Records

Enhanced Verification

CURP → Name Check → DOB Check → NSS → RFC → Criminal Records → Sanctions

Create Person - Initiate CURP validation
Get Reports - Retrieve CURP results
Get Report Details - Detailed CURP data
Update Reports - Refresh CURP validation

Name Check Reference - Name validation
DOB Check Reference - Date of birth validation
Mexico Country Guide - Mexico-specific information
Legal Glossary - Legal terminology