$re = '/(?:^|\t)(?:\d+|KY\d+|([^\t]+))(?=\t|$)/m';
$str = '1025164 HERBEX IBERIA, S.L.U. KY01 4600292091
1016379 DRISCOLL´S OF EUROPE B.V. KY01 4600322589
1008809 KY01 LANDGARD NORD OBST & GEMÜSE GM 4600347315
1008835 C.A.S.I. : COOPERATIVA PROVINC KY01 4600348112
1019258 SYDGRÖNT EKONOMISK FÖRENING KY02 460034342
1019258 3 M SVENSKA AB KY02 460034342
1019258 460034342 3 M SVENSKA AB KY02
3 M SVENSKA AB KY02 460034342 1019258
1019258 460034342 KY02 3 M SVENSKA AB';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php