Index: sites/all/modules/contrib/phone/phone.nl.inc
===================================================================
--- sites/all/modules/contrib/phone/phone.nl.inc	(revision )
+++ sites/all/modules/contrib/phone/phone.nl.inc	(revision )
@@ -6,6 +6,15 @@
  * CCK Field for Dutch phone numbers.
  */
 
+define("PHONE_NL_REGEX", '/
+  ((?:\+31[ ]?|[0]{1})[6]{1}[-\s]*[1-9]{1}[\s]*([0-9]{1}[\s]*){7})				# Mobile phonenumber
+  |
+  ((?:\+31[ ]?|[0]{1}){1}[1-9]{1}[0-9]{2}[-\s]*[1-9]{1}[\s]*([0-9]{1}[\s]*){5})		# Phonenumber with 4 digit area code
+  |
+  ((?:\+31[ ]?|[0]{1}){1}[1-9]{1}[0-9]{1}[-\s]*[1-9]{1}[\s]*([0-9]{1}[\s]*){6})		# Phonenumber with 3 digit area code
+  /x'
+);
+
 function phone_nl_metadata() {
   // These strings are translated using t() on output.
   return array(
@@ -40,17 +49,8 @@
     	123 456 7890
   */
 
-  // define regular expression
-  $regex = '/
-  ([0]{1}[6]{1}[-\s]+[1-9]{1}[\s]*([0-9]{1}[\s]*){7})				# Mobile phonenumber
-  |
-  ([0]{1}[1-9]{1}[0-9]{2}[-\s]+[1-9]{1}[\s]*([0-9]{1}[\s]*){5})		# Phonenumber with 4 digit area code
-  |
-  ([0]{1}[1-9]{1}[0-9]{1}[-\s]+[1-9]{1}[\s]*([0-9]{1}[\s]*){6})		# Phonenumber with 3 digit area code
-  /x';
-
   // return true if valid, false otherwise
-  return (bool) preg_match($regex, $phonenumber);
+  return (bool) preg_match(PHONE_NL_REGEX, $phonenumber);
 }
 
 /**
@@ -63,17 +63,9 @@
 
   $areacode = $localnumber = '';
   // Mobile number
-  if (preg_match('/([0]{1}[6]{1}[-\s]+[1-9]{1}[\s]*([0-9]{1}[\s]*){7})/', $phonenumber)) {
-        preg_match('/([0]{1}[6]{1})[-\s]+([1-9]{1}[\s]*([0-9]{1}[\s]*){7})/', $phonenumber, $matches);
+  if (preg_match(PHONE_NL_REGEX, $phonenumber)) {
+    preg_match(PHONE_NL_REGEX, $phonenumber, $matches);
-    }
+  }
-  // Phonenumber with 4 digit area code
-  if (preg_match('/([0]{1}[1-9]{1}[0-9]{2}[-\s]+[1-9]{1}[\s]*([0-9]{1}[\s]*){5})/', $phonenumber)) {
-      preg_match('/([0]{1}[1-9]{1}[0-9]{2})[-\s]+([1-9]{1}[\s]*([0-9]{1}[\s]*){5})/', $phonenumber, $matches);
-  }
-  // Phonenumber with 3 digit area code
-  if (preg_match('/([0]{1}[1-9]{1}[0-9]{1}[-\s]+[1-9]{1}[\s]*([0-9]{1}[\s]*){6})/', $phonenumber)) {
-      preg_match('/([0]{1}[1-9]{1}[0-9]{1})[-\s]+([1-9]{1}[\s]*([0-9]{1}[\s]*){6})/', $phonenumber, $matches);
-  }
 
   $areacode = $matches[1];
   $localnumber = preg_replace('/ /', '', $matches[2]);