For the electronic B2C stuff in the EU, the requirement is two non-conflicting sources. Something like geolocation and card billing address should suffice in mo

For the electronic B2C stuff in the EU, the requirement is two non-conflicting sources. Something like geolocation and card billing address should suffice in most cases (assuming you have access to the customer's IP address and they're paying by card, which is surely a fairly common situation for a SaaS).