diff --git a/addons/sms/models/mail_thread.py b/addons/sms/models/mail_thread.py
index 1fb62a72de4..a439487e4e9 100644
--- a/addons/sms/models/mail_thread.py
+++ b/addons/sms/models/mail_thread.py
@@ -39,8 +39,8 @@ class MailThread(models.AbstractModel):
             if not partners:
                 partners = self._get_default_sms_recipients()
 
-                # Collect numbers, we will consider the message to be sent if at least one number can be found
-                numbers = list(set([i.mobile for i in partners if i.mobile]))
+            # Collect numbers, we will consider the message to be sent if at least one number can be found
+            numbers = list(set([i.mobile for i in partners if i.mobile]))
 
         if numbers:
             try:
diff --git a/addons/sms/wizard/send_sms.py b/addons/sms/wizard/send_sms.py
index 15d284e0879..f25bedb72ab 100644
--- a/addons/sms/wizard/send_sms.py
+++ b/addons/sms/wizard/send_sms.py
@@ -44,8 +44,8 @@ class SendSMS(models.TransientModel):
                 return number
             if not phonenumbers.is_possible_number(phone_nbr) or not phonenumbers.is_valid_number(phone_nbr):
                 return number
-            phone_fmt = phonenumbers.PhoneNumberFormat.INTERNATIONAL
-            return phonenumbers.format_number(phone_nbr, phone_fmt).replace(' ', '')
+            phone_fmt = phonenumbers.PhoneNumberFormat.E164
+            return phonenumbers.format_number(phone_nbr, phone_fmt)
         else:
             return number
 
@@ -61,12 +61,11 @@ class SendSMS(models.TransientModel):
     @api.model
     def default_get(self, fields):
         result = super(SendSMS, self).default_get(fields)
-
         active_model = self.env.context.get('active_model')
-        model = self.env[active_model]
 
-        records = self._get_records(model)
-        if getattr(records, '_get_default_sms_recipients'):
+        if not self.env.context.get('default_recipients') and active_model and hasattr(self.env[active_model], '_get_default_sms_recipients'):
+            model = self.env[active_model]
+            records = self._get_records(model)
             partners = records._get_default_sms_recipients()
             phone_numbers = []
             no_phone_partners = []
@@ -83,12 +82,12 @@ class SendSMS(models.TransientModel):
         return result
 
     def action_send_sms(self):
-        numbers = self.recipients.split(',')
+        numbers = [number.strip() for number in self.recipients.split(',') if number.strip()]
 
         active_model = self.env.context.get('active_model')
-        model = self.env[active_model]
-        records = self._get_records(model)
-        if getattr(records, 'message_post_send_sms'):
+        if active_model and hasattr(self.env[active_model], 'message_post_send_sms'):
+            model = self.env[active_model]
+            records = self._get_records(model)
             records.message_post_send_sms(self.message, numbers=numbers)
         else:
             self.env['sms.api']._send_sms(numbers, self.message)