diff --git a/addons/l10n_ch/models/account_invoice.py b/addons/l10n_ch/models/account_invoice.py
index f0c6eae22ff..d8650bd1e03 100644
--- a/addons/l10n_ch/models/account_invoice.py
+++ b/addons/l10n_ch/models/account_invoice.py
@@ -246,10 +246,7 @@ class AccountMove(models.Model):
         for inv in self:
             if inv.move_type == 'in_invoice' and inv.company_id.country_id.code == "CH":
                 partner_bank = inv.partner_bank_id
-                if partner_bank:
-                    needs_isr_ref = partner_bank._is_qr_iban() or partner_bank._is_isr_issuer()
-                else:
-                    needs_isr_ref = False
+                needs_isr_ref = partner_bank._is_qr_iban() or partner_bank._is_isr_issuer()
                 if needs_isr_ref and not inv._has_isr_ref():
                     inv.l10n_ch_isr_needs_fixing = True
                     continue
diff --git a/addons/l10n_ch/models/res_bank.py b/addons/l10n_ch/models/res_bank.py
index 6011ce31f30..cd0e8c6a1ef 100644
--- a/addons/l10n_ch/models/res_bank.py
+++ b/addons/l10n_ch/models/res_bank.py
@@ -263,8 +263,6 @@ class ResPartnerBank(models.Model):
         QR-codes. They are formed like regular IBANs, but are actually something
         different.
         """
-        self.ensure_one()
-
         return self.acc_type == 'iban' \
                and self._check_qr_iban_range(self.sanitized_acc_number)