You can enter your VAT ID at checkout when signing up for a paid plan on Walls.io:
Please make sure to enter your accurate business name and address.
If you forgot to enter your VAT ID or need any changes after you signed up, please contact our support team for help.
Tax with US-customers
For sales tax refunds, you can submit a copy of your tax exemption certificate or other supporting paperwork issued by the state government via https://fastspring.com/consumer-support-form/tax-vat-gst/ along with your order reference / order ID, and the support team of our payment provider FastSpring will refund the sales tax back to the original payment account.
From the time their support team receives a ticket with a tax refund request, it should take no more than 24-48 hours (and probably less) until the refund has been processed and they reply to you. After that, it can take a few business days for the funds to post back to your payment account.
In case you have further questions, don't hesitate to contact the support team via the chat or support@walls.io!