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CLABE Validator


JavaScript library to analyze or create a CLABE number for a Mexican bank account

License:MIT npm Vulnerabilities Hits Build

CLABE (Clave Bancaria Estandarizada — Spanish for "standardized banking code") is a banking standard from the Mexican Bank Association (Asociación de Bancos de México — ABM) for uniform numbering of bank accounts.  CLABE numbers are 18 digits long.  See:

A) Online Form

Try it out:

B) Setup

Web browser

Include in a web page:

<script src=clabe.min.js></script>

or from the CDN:

<script src=></script>

Node.js server

Install package for node:

$ npm install clabe-validator

Import package:

import { clabe } from 'clabe-validator';

Or for older CommonJS/UMD environments:

const { clabe } = require('clabe-validator');  //deprecated -- use ES modules instead

C) Validator Usage

Pass the CLABE number as an 18-character string into clabe.validate(clabeNum).

1. Example JavaScript code

const clabeNum =   '002010077777777771';
const clabeCheck = clabe.validate(clabeNum);
console.log(clabeCheck.ok ? '¡Que bueno!' : '¡Muy mal!');
console.log('Your bank: ' +;

2. Example JSON result for a valid CLABE number

   ok:       true,
   formatOk: true,
   error:    null,
   message:  'Valid',
   clabe:    '002010077777777771',
   tag:      'BANAMEX',
   bank:     'Banco Nacional de México',
   city:     'Aguascalientes MX-AGU',
   multiple: false,
   total:    1,
   account:  '07777777777',
   code:     { bank: '002', city: '010' },
   checksum: 1,

3. Example JSON result for an invalid CLABE number

   ok:       false,
   formatOk: true,
   error:    'invalid-city',
   message:  'Invalid city code: 000',

The formatOk field indicates if the CLABE's length and checksum are both valid (even if the bank code or city code are unknown).

4. Possible errors

Error code Error message Format Ok
invalid-length Must be exactly 18 digits long false
invalid-characters Must be only numeric digits (no letters) false
invalid-checksum Invalid checksum, last digit should be: [DIGIT] false
invalid-bank Invalid bank code: [CODE] true
invalid-city Invalid city code: [CODE] true

D) Calculator Usage

Pass the bank code, city code, and account number into clabe.calculate(bankCode, cityCode, accountNumber) and get the 18-character CLABE number back.

const clabeNum = clabe.calculate(2, 10, 7777777777);
console.log(clabeNum === '002010077777777771');  //true

E) TypeScript Declarations

The TypeScript Declaration File file is clabe.d.ts in the dist folder.

The clabe.validate(clabeNum: string) function returns a ClabeCheck object:

type ClabeCheck = {
   ok:       boolean,        //todo está bien
   formatOk: boolean,        //valid length and checksum
   error:    string | null,  //failure code, example: 'invalid-city'
   message:  string,         //displayable status information
   clabe:    string | null,  //full 18-digit number
   tag:      string | null,  //bank short name, example: 'BANAMEX'
   bank:     string | null,  //bank long name, example: 'Banco Nacional'
   city:     string | null,  //branch or plaza name
   multiple: boolean,        //more than one city share the same code
   total:    number,         //number of cities
   account:  string,         //11-digit zero-padded bank account number
   code:     { bank: string, city: string },  //3-digit codes
   checksum: number | null,  //control digit (0 to 9)

Example TypeScript usage with explicit types:

import { clabe, ClabeCheck } from 'clabe-validator';

const clabeNum:   string =     '002010077777777771';
const clabeCheck: ClabeCheck = clabe.validate(clabeNum);  //{ ok: true, error: null, ... }
const bankCode:   string =;      //'002'

F) Contributor Notes

To be a contributor, fork the project and run the commands npm install and npm test on your local clone.  Make your edits and rerun the tests.  Pull requests welcome.

G) Genesis

The origin of this project goes back to when I needed to send money to Guanajuato, Mexico to pay nurses who were providing medical care of a relative.  I was initially unable to transfer funds because the money transfer service reported that the CLABE number I supplied was invalid.  Through a little sleuthing and a lot of luck, I discovered that a financial services company had accidentally omitted the very last modulo operation in their CLABE checksum calculation.  The result was that Mexican bank account numbers with certain combinations of digits were erroneously rejected.

This project was created to fix the checksum bug.  It is an open source community project and is not supported by any company.

Feel free to submit questions at:

CLABE Validator code is open source under the MIT License, and the documentation is published under the CC BY-SA 4.0 license.