diff --git a/htdocs/webservices/server_contact.php b/htdocs/webservices/server_contact.php
index ec652e80074..e0d76a0eb90 100644
--- a/htdocs/webservices/server_contact.php
+++ b/htdocs/webservices/server_contact.php
@@ -627,9 +627,15 @@ function updateContact($authentication,$contact)
 	$error=0;
 	$fuser=check_authentication($authentication,$error,$errorcode,$errorlabel);
 	// Check parameters
-	if (empty($contact['id']))	{
-		$error++; $errorcode='KO'; $errorlabel="Contact id is mandatory.";
+	if (empty($contact['id']) && empty($contact['ref_ext'])	{
+		$error++; $errorcode='KO'; $errorlabel="Contact id or ref_ext is mandatory.";
 	}
+	// Check parameters
+    if (! $error && ($id && $ref_ext))
+    {
+        $error++;
+        $errorcode='BAD_PARAMETERS'; $errorlabel="Parameter id and ref_ext can't be all provided. You must choose one of them.";
+    }
 
 	if (! $error)
 	{
@@ -638,7 +644,7 @@ function updateContact($authentication,$contact)
 		include_once DOL_DOCUMENT_ROOT.'/core/lib/company.lib.php';
 
 		$object=new Contact($db);
-		$result=$object->fetch($contact['id']);
+		$result=$object->fetch($contact['id'],0,$contact['ref_ext']);
 
 		if (!empty($object->id)) {