Validar NIF, CIF y NIE en PHP, actualizado 2024

ow-validate-ident.php

function validateIdent( $ident = '' ) {

		$BASE_REG_EXP = '/((^[A-Z]{1}[0-9]{7}[A-Z0-9]{1}$|^[T]{1}[A-Z0-9]{8}$)|^[0-9]{8}[A-Z]{1}$)/';
		$CIF_REG_EXP  = '/^[ABCDEFGHJNPQRSUVW]{1}/';
		$NIF_REG_EXP  = '/(^[0-9]{8}[A-Z]{1}$)/';
		$NIE_REG_EXP  = '/^[XYZ]{1}/';
		$NIS_REG_EXP  = '/^[KLM]{1}/';
		$NID_STR_SEQ  = 'TRWAGMYFPDXBNJZSQVHLCKE';

		$ident = mb_strtoupper( $ident );
		if ( ! preg_match( $BASE_REG_EXP, $ident ) ) {
			return false;
		}

		$ident_chars = str_split( $ident );
		if ( preg_match( $NIF_REG_EXP, $ident ) ) {
			if ( $ident_chars[8] == substr( $NID_STR_SEQ,
					substr( $ident, 0, 8 ) % 23, 1 ) ) {
				return true;
			} else {
				return false;
			}
		}

		if ( preg_match( $NIE_REG_EXP, $ident ) ) {
			if ( $ident_chars[8] == substr( $NID_STR_SEQ,
					substr( str_replace( [ 'X', 'Y', 'Z' ], [ '0', '1', '2' ], $ident ),
						0, 8 ) % 23, 1 ) ) {
				return true;
			} else {
				return false;
			}
		}

		$check_sum = $ident_chars[2] + $ident_chars[4] + $ident_chars[6];
		for ( $i = 1; $i < 8; $i += 2 ) {
			$check_sum += intval( substr( ( 2 * $ident_chars[ $i ] ), 0, 1 ) ) +
			              intval( substr( ( 2 * $ident_chars[ $i ] ), 1, 1 ) );
		}
		$check_sum = 10 - intval( substr( $check_sum, strlen( $check_sum ) - 1, 1 ) );
		$check_asc = $ident_chars[8] == chr( 64 + $check_sum );

		if ( preg_match( $NIS_REG_EXP, $ident ) ) {
			if ( $check_asc ||
			     $ident_chars[8] == substr( $NID_STR_SEQ, substr( $ident, 1, 8 ) % 23, 1 ) ) {
				return true;
			} else {
				return false;
			}
		}

		if ( preg_match( $CIF_REG_EXP, $ident ) ) {
			if ( $check_asc ||
			     $ident_chars[8] == substr( $check_sum, strlen( $check_sum ) - 1, 1 ) ) {
				return true;
			}
		}

		return false;
	}