Mini Shell

/*
 * Código de identificación fiscal ( CIF ) is the tax identification code for Spanish legal entities
 * Further rules can be found in Spanish on http://es.wikipedia.org/wiki/C%C3%B3digo_de_identificaci%C3%B3n_fiscal
 */
$.validator.addMethod( "cifES", function( value ) {
	"use strict";

	var num = [],
		controlDigit, sum, i, count, tmp, secondDigit;

	value = value.toUpperCase();

	// Quick format test
	if ( !value.match( "((^[A-Z]{1}[0-9]{7}[A-Z0-9]{1}$|^[T]{1}[A-Z0-9]{8}$)|^[0-9]{8}[A-Z]{1}$)" ) ) {
		return false;
	}

	for ( i = 0; i < 9; i++ ) {
		num[ i ] = parseInt( value.charAt( i ), 10 );
	}

	// Algorithm for checking CIF codes
	sum = num[ 2 ] + num[ 4 ] + num[ 6 ];
	for ( count = 1; count < 8; count += 2 ) {
		tmp = ( 2 * num[ count ] ).toString();
		secondDigit = tmp.charAt( 1 );

		sum += parseInt( tmp.charAt( 0 ), 10 ) + ( secondDigit === "" ? 0 : parseInt( secondDigit, 10 ) );
	}

	/* The first (position 1) is a letter following the following criteria:
	 *	A. Corporations
	 *	B. LLCs
	 *	C. General partnerships
	 *	D. Companies limited partnerships
	 *	E. Communities of goods
	 *	F. Cooperative Societies
	 *	G. Associations
	 *	H. Communities of homeowners in horizontal property regime
	 *	J. Civil Societies
	 *	K. Old format
	 *	L. Old format
	 *	M. Old format
	 *	N. Nonresident entities
	 *	P. Local authorities
	 *	Q. Autonomous bodies, state or not, and the like, and congregations and religious institutions
	 *	R. Congregations and religious institutions (since 2008 ORDER EHA/451/2008)
	 *	S. Organs of State Administration and regions
	 *	V. Agrarian Transformation
	 *	W. Permanent establishments of non-resident in Spain
	 */
	if ( /^[ABCDEFGHJNPQRSUVW]{1}/.test( value ) ) {
		sum += "";
		controlDigit = 10 - parseInt( sum.charAt( sum.length - 1 ), 10 );
		value += controlDigit;
		return ( num[ 8 ].toString() === String.fromCharCode( 64 + controlDigit ) || num[ 8 ].toString() === value.charAt( value.length - 1 ) );
	}

	return false;

}, "Please specify a valid CIF number." );