Hi I would like to add spaces between numbers in phonenumbers on invoice reports.

I know there is the base_phone module which can provide some facility to do it. I follow the advices in the module description and add a field like the following in my xml file :

<span t-esc="o.partner_id and o.partner_id.phone and format(o.partner_id.phone, phone=True, phone_format='national') or ''" />

But a NoneType Exception is raised.

If I replace partner_id with user_id it works as expected.

Could someone help ?