diff --git a/odex25_transactions/exp_transation_letters/models/res_users.py b/odex25_transactions/exp_transation_letters/models/res_users.py
index 8de2eb11e..5f8d8c39e 100644
--- a/odex25_transactions/exp_transation_letters/models/res_users.py
+++ b/odex25_transactions/exp_transation_letters/models/res_users.py
@@ -15,13 +15,14 @@ class ResUsers(models.Model):
         attachment_id = context.get('default_attachment_id') if context else None
 
         # Custom logic before updating the record
-        if 'sign_signature' in vals and letter_id:
+        if letter_id:
             # Ensure letter_id is a valid recordset
             letter_record = self.env['letters.letters'].browse(letter_id)
-            attachment_record = self.env['cm.attachment.rule'].browse(attachment_id)
             if letter_record.exists():
-                letter_record.new_signature = vals.get('sign_signature')
+                letter_record.new_signature = vals.get('sign_signature') if vals.get('sign_signature') else self.env.user.sign_signature
                 letter_record.action_generate_attachment()
+        if attachment_id:
+            attachment_record = self.env['cm.attachment.rule'].browse(attachment_id)
             if attachment_record:
                 attachment_record.signed = True