diff --git a/addons/account/controllers/portal.py b/addons/account/controllers/portal.py
index 5f4d5cffb40..c59286cf381 100644
--- a/addons/account/controllers/portal.py
+++ b/addons/account/controllers/portal.py
@@ -143,6 +143,8 @@ class PortalAccount(CustomerPortal):
             return request.make_response(attachments.raw, list(headers.items()))
 
         elif report_type in ('html', 'pdf', 'text'):
+            has_generated_invoice = bool(invoice_sudo.invoice_pdf_report_id)
+            request.update_context(proforma_invoice=not has_generated_invoice)
             return self._show_report(model=invoice_sudo, report_type=report_type, report_ref='account.account_invoices', download=download)
 
         values = self._invoice_get_page_view_values(invoice_sudo, access_token, **kw)
diff --git a/addons/account/models/ir_actions_report.py b/addons/account/models/ir_actions_report.py
index a1d46948c50..b2216f0eb1b 100644
--- a/addons/account/models/ir_actions_report.py
+++ b/addons/account/models/ir_actions_report.py
@@ -75,3 +75,9 @@ class IrActionsReport(models.Model):
             master_report = self.env.ref(f"account.{master_xmlid}", raise_if_not_found=False)
             if master_report and master_report in self:
                 raise UserError(_("You cannot delete this report (%s), it is used by the accounting PDF generation engine.", master_report.name))
+
+    def _get_rendering_context(self, report, docids, data):
+        data = super()._get_rendering_context(report, docids, data)
+        if self.env.context.get('proforma_invoice'):
+            data['proforma'] = True
+        return data