diff --git a/addons/mail/static/src/js/field_char.js b/addons/mail/static/src/js/field_char.js
new file mode 100644
index 00000000000..1a1b90ec875
--- /dev/null
+++ b/addons/mail/static/src/js/field_char.js
@@ -0,0 +1,56 @@
+odoo.define('sms.onchange_in_keyup', function (require) {
+"use strict";
+
+var FieldChar = require('web.basic_fields').FieldChar;
+FieldChar.include({
+
+    //--------------------------------------------------------------------------
+    // Public
+    //-------------------------------------------------------------------------
+
+    /**
+     * Support a key-based onchange in text field. In order to avoid too much
+     * rpc to the server _triggerOnchange is throttled (once every second max)
+     *
+     */
+    init: function () {
+        this._super.apply(this, arguments);
+        this._triggerOnchange = _.throttle(this._triggerOnchange, 1000, {leading: false});
+    },
+
+
+    //--------------------------------------------------------------------------
+    // Handlers
+    //--------------------------------------------------------------------------
+
+    /**
+     * Trigger the 'change' event at key down. It allows to trigger an onchange
+     * while typing which may be interesting in some cases. Otherwise onchange
+     * is triggered only on blur.
+     *
+     * @override
+     * @private
+     */
+    _onKeydown: function () {
+        this._super.apply(this, arguments);
+        if (this.nodeOptions.onchange_on_keydown) {
+            this._triggerOnchange();
+        }
+    },
+
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+    /**
+     * Triggers the 'change' event to refresh the value. Throttled at init to
+     * avoid spaming server.
+     *
+     * @private
+     */
+    _triggerOnchange: function () {
+        this.$input.trigger('change');
+    },
+});
+
+});
diff --git a/addons/mail/views/assets.xml b/addons/mail/views/assets.xml
index 09aff4897af..f582e344010 100644
--- a/addons/mail/views/assets.xml
+++ b/addons/mail/views/assets.xml
@@ -11,6 +11,7 @@
             <xpath expr="." position="inside">
                 <script type="text/javascript" src="/mail/static/src/js/many2many_tags_email.js"></script>
                 <script type="text/javascript" src="/mail/static/src/js/many2one_avatar_user.js"></script>
+                <script type="text/javascript" src="/mail/static/src/js/field_char.js"></script>
 
                 <!-- Services -->
                 <script type="text/javascript" src="/mail/static/src/js/services/mail_manager.js"></script>
diff --git a/addons/sms/wizard/sms_composer_views.xml b/addons/sms/wizard/sms_composer_views.xml
index 543b731f360..b1be27ca32b 100644
--- a/addons/sms/wizard/sms_composer_views.xml
+++ b/addons/sms/wizard/sms_composer_views.xml
@@ -45,7 +45,7 @@
                             attrs="{'invisible': [('comment_single_recipient', '=', False)]}"/>
                         <div attrs="{'invisible': [('comment_single_recipient', '=', False)]}">
                             <field name="recipient_single_description" class="oe_inline"/>
-                            <field name="recipient_single_number_itf" class="oe_inline" nolabel="1"/>
+                            <field name="recipient_single_number_itf" class="oe_inline" nolabel="1" options="{'onchange_on_keydown': True}"/>
                         </div>
                                                 
                         <field name="body" widget="sms_widget"/>