diff --git a/submodules/devices/devices.js b/submodules/devices/devices.js
index ea82e92a..ca00977a 100644
--- a/submodules/devices/devices.js
+++ b/submodules/devices/devices.js
@@ -359,7 +359,7 @@ define(function(require){
 			monster.ui.protectField(templateDevice.find('#sip_password'), templateDevice);
 
 			monster.ui.tooltips(templateDevice);
-			templateDevice.find('#mac_address').mask("hh:hh:hh:hh:hh:hh", { placeholder:" " });
+			templateDevice.find('#mac_address').mask('FF:FF:FF:FF:FF:FF', {translation: {"F": { pattern:/[A-Fa-f0-9]/ }}});
 			templateDevice.find('.chosen-feature-key-user').chosen({ search_contains: true, width: 'inherit' });
 
 			if(!(data.media.encryption.enforce_security)) {
diff --git a/submodules/groups/groups.css b/submodules/groups/groups.css
index 4d828893..1e1e704d 100644
--- a/submodules/groups/groups.css
+++ b/submodules/groups/groups.css
@@ -338,6 +338,11 @@
 	white-space: nowrap;
 }
 
+#groups_container .list-wrapper .item-row .input-extension {
+	margin: 0 5px 2px 5px;
+	width: 50px;
+}
+
 #groups_container .list-wrapper .item-row > * {
 	display: inline-block;
 	padding: 10px;
@@ -347,10 +352,7 @@
 
 #groups_container .list-wrapper .item-row button {
 	margin-right: 15px;
-	padding: 2px;
-	width: 80px;
 }
-
 #groups_container .list-wrapper .empty-search-row,
 #groups_container .list-wrapper .empty-row {
 	display: none;
diff --git a/submodules/groups/groups.js b/submodules/groups/groups.js
index 69a19bd2..682d4ab3 100644
--- a/submodules/groups/groups.js
+++ b/submodules/groups/groups.js
@@ -275,6 +275,8 @@ define(function(require){
 
 					monster.ui.validate(groupForm);
 
+					groupForm.find('#inputExtension').mask('99ZZZZZZZZZZZZZZ', {translation:  {'Z': {pattern: /[0-9]/, optional: true}}});
+
 					groupTemplate.find('#create_group').on('click', function() {
 						if(monster.ui.valid(groupForm)) {
 							var formattedData = self.groupsCreationMergeData(data, groupTemplate);
@@ -1248,6 +1250,8 @@ define(function(require){
 						newLineTemplate = $(monster.template(self, 'groups-newExtension', dataTemplate)),
 						$listExtensions = template.find('.list-assigned-items');
 
+					newLineTemplate.find('.input-extension').mask('99ZZZZZZZZZZZZZZ', {translation:  {'Z': {pattern: /[0-9]/, optional: true}}});
+
 					listExtension.push(lastExtension);
 					$listExtensions.find('.empty-row').hide();
 
diff --git a/submodules/users/users.js b/submodules/users/users.js
index 01ef454d..dbe2ef26 100644
--- a/submodules/users/users.js
+++ b/submodules/users/users.js
@@ -587,6 +587,8 @@ define(function(require){
 						var originalData = self.usersFormatAddUser(results),
 							userTemplate = $(monster.template(self, 'users-creation', originalData));
 
+						userTemplate.find('#extension').mask('99ZZZZZZZZZZZZZZ', {translation:  {'Z': {pattern: /[0-9]/, optional: true}}});
+
 						monster.ui.validate(userTemplate.find('#form_user_creation'), {
 							rules: {
 								'callflow.extension': {
@@ -717,6 +719,8 @@ define(function(require){
 					newLineTemplate = $(monster.template(self, 'users-newExtension', dataTemplate)),
 					listExtensions = template.find('.extensions .list-assigned-items');
 
+				newLineTemplate.find('.input-extension ').mask('99ZZZZZZZZZZZZZZ', {translation:  {'Z': {pattern: /[0-9]/, optional: true}}});
+
 				listExtensions.find('.empty-row').hide();
 
 				listExtensions.append(newLineTemplate);