diff --git a/addons/account_edi_ubl_cii/models/account_move_send.py b/addons/account_edi_ubl_cii/models/account_move_send.py
index 98cc234a255..0bb050d2e42 100644
--- a/addons/account_edi_ubl_cii/models/account_move_send.py
+++ b/addons/account_edi_ubl_cii/models/account_move_send.py
@@ -34,7 +34,7 @@ class AccountMoveSend(models.Model):
             code_to_label = dict(wizard.move_ids.partner_id._fields['ubl_cii_format'].selection)
             codes = wizard.move_ids.partner_id.mapped('ubl_cii_format')
             if any(codes):
-                wizard.checkbox_ubl_cii_label = ", ".join(code_to_label[c] for c in codes)
+                wizard.checkbox_ubl_cii_label = ", ".join(code_to_label[c] for c in set(codes) if c)
             else:
                 wizard.checkbox_ubl_cii_label = False