$re = '/(.*)\s[A-Z]{2,}[0-9]{2}.*/m';
$str = 'C.H. Robinson o/Vienna SZO13G9, SZO6P34, Roger Moor
Bus Trans Mouse PT513AA, Anthony Hopkins
P.H.U TRI-POL ZMI14A8
Mank WXL89040, Jared Leto';
$subst = "$1";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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