diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index 4ce41e9c7d7..72a82fbca27 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -396,11 +396,11 @@ class AccountMove(models.Model):
                     self.partner_id = False
                     return {'warning': warning}
 
-        if self.is_sale_document(include_receipts=True) and self.partner_id.property_payment_term_id:
-            self.invoice_payment_term_id = self.partner_id.property_payment_term_id
+        if self.is_sale_document(include_receipts=True) and self.partner_id:
+            self.invoice_payment_term_id = self.partner_id.property_payment_term_id or self.invoice_payment_term_id
             new_term_account = self.partner_id.commercial_partner_id.property_account_receivable_id
-        elif self.is_purchase_document(include_receipts=True) and self.partner_id.property_supplier_payment_term_id:
-            self.invoice_payment_term_id = self.partner_id.property_supplier_payment_term_id
+        elif self.is_purchase_document(include_receipts=True) and self.partner_id:
+            self.invoice_payment_term_id = self.partner_id.property_supplier_payment_term_id or self.invoice_payment_term_id
             new_term_account = self.partner_id.commercial_partner_id.property_account_payable_id
         else:
             new_term_account = None