$re = '/(?i)quote\s*(\d+)/m';
$str = 'sjhsh QUOTE 234566
sdsds customer call QUote 239876 Call back
adsdfh unknown call from customer QUOTE 189067 sdkjsd woieweio
QUOTE 657894 customer called for service
QUOTE 657894 customer called for service QUOTE 657894 customer called for service
No qte';
preg_match_all($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