Validate-rfc NPM

Validate RFC

npm.io npm.io

A simple and lightweight library to validate Mexican RFCs (Tax ID).

Install

NodeJS

Use NPM:

$ npm install --save validate-rfc

Or YARN:

$ yarn add validate-rfc

Browser

Add the script to your project:

<!-- Latest version -->
<script src="https://cdn.jsdelivr.net/gh/manuelmhtr/validate-rfc@latest/dist/index.js" type="text/javascript"></script>

<!-- Or specify a version -->
<script src="https://cdn.jsdelivr.net/gh/manuelmhtr/validate-rfc@v2.0.2/dist/index.js" type="text/javascript"></script>

<!-- This will export a global function "validateRfc": -->
<script type="text/javascript">
  var data = validateRfc('mhtr93041179a');
  console.log(data);
</script>

API

The library only exposes a single function (.validateRfc).

.validateRfc(rfc)

Checks whether a string is a valid RFC and returns validation details.

Parameters

Parameter	Type	Description
`rfc`	String	The RFC to be validated.
`options`	Object	Settings (Optional).
`options.omitVerificationDigit`	Boolean	When `true`, the Check digit is omitted from the validation (Default: `false`). This option is useful since there are some RFCs with an invalid Check digit that are recognized as valid by the Mexican authorities (See Known issues).

Response

It returns a plain object with the values:

Parameter	Type	Description
`isValid`	Boolean	Indicates if the string is a valid RFC.
`rfc`	String	The formatted RFC (uppercase, with no white spaces or symbols). Returns `null` when input is an invalid RFC.
`type`	String	The classification of the provided RFC. Values can be `person` for a legal person, `company` for companies, `generic` for the generic RFC "XAXX010101000" ir `foreign` for the RFC "XEXX010101000" which is used by foreign people. Returns `null` when input is an invalid RFC.
`errors`	ArrayString	In case the RFC is invalid, the reasons why the RFC is invalid will be listed here.

Possible errors values and they description are:

Error	Descripción
`INVALID_FORMAT`	The format is invalid, that means, the string does not meet with the required length or expected structure. Eg: `XYZ` because clearly is not an RFC.
`INVALID_DATE`	The string may have the correct format, but digits generate an invalid date. Eg: `MHTR815511A70` because it refers to month `55`.
`INVALID_VERIFICATION_DIGIT`	The string has a valid format, but the last character (check digit) is invalid. Eg: `MHTR810511A79` ends with `9` but it is expected to end with `2`.
`FORBIDDEN_WORD`	The string contains one of the inconvenient words that cannot be included in an RFC. Eg: `FETO930411792` the initials make the word `FETO` (fetus, LOL).

Example

const validateRfc = require('validate-rfc');

const response = validateRfc('mhtr93041179a');
console.log(response);

/*
Prints:

{
  isValid: true,
  rfc: 'MHTR93041179A',
  type: 'person'
}

*/

const response = validateRfc('This is not an RFC');
console.log(response);

/*
Prints:

{
  isValid: false,
  rfc: null,
  type: null,
  errors: ['INVALID_FORMAT']
}

*/

Tests

Run the test with the command:

$ yarn test

Known issues

Check digit mismatches

Some RFCs registered by the SAT (Mexican taxing bureau) does not pass the Check digit validation. For instance, LME060822IH5 is a valid RFC and able to be invoices according the SAT official validator, however its Check digit should be 3 rather than 5. Therefore in those cases, this library returns isValid as false and the error INVALID_VERIFICATION_DIGIT.

Solutions: 1. If you find one of these cases, add it to the list of valid RFCs. Upper-cased and sorted alphabetically. By adding them to the list you are supporting the documentation of such cases and preventing from returning an error the next time. 2. Use the option omitVerificationDigit to ignore the Check digit validation. It has the advantage of being a faster solution and covers all the cases, but many invalid RFCs will pass the validation.

References: