Note: the info in this article is relevant for all Legacy subscriptions paid via the FastSpring company.
If you pay with a card, the field for entering VAT ID will appear at the initial stage of the payment process.
In case you pay with PayPal, once you return from FastSpring to PayPal, there should be specified field for VAT ID, as well.
For better understanding, the process should be as follows: when processing payment you log in to PayPal, then you are directed to FastSpring and then back to PayPal.
Field for applying VAT ID will appear on the final stage.