diff --git a/l10n_it_fatturapa_out/wizard/efattura.py b/l10n_it_fatturapa_out/wizard/efattura.py
index 3fa5a6cd6616..a4321f0248e6 100644
--- a/l10n_it_fatturapa_out/wizard/efattura.py
+++ b/l10n_it_fatturapa_out/wizard/efattura.py
@@ -338,9 +338,18 @@ def to_xml(self, env):
         content = etree.tostring(root, xml_declaration=True, encoding="utf-8")
         return content
 
+    def _get_company_from_invoices(self, invoices):
+        company_id = invoices.mapped("company_id")
+        if len(company_id) > 1:
+            raise UserError(
+                    _("Invoices %s must belong to the same company.")
+                    % invoices.mapped("number")
+                )
+        return company_id
+
     def __init__(self, wizard, partner_id, invoices, progressivo_invio):
         self.wizard = wizard
-        self.company_id = wizard.env.company
+        self.company_id = self._get_company_from_invoices(invoices) or wizard.env.company
         self.partner_id = partner_id
         self.invoices = invoices
         self.progressivo_invio = progressivo_invio