Intervaarium Requisites

Constitution (in Estonian)
A Copy of The Registry card
(List of owners and management, in Estonian.)
Registration Number 80341809
Aaddress Sihi 111 (Kaare 2), Tallinn, 11618, Estonia
Contact, +372-5-515-537
Bank Account at Nordea EE771700017003220155

The registration status of the Intervaarium can be verified from

What regards to the European Union wide taxation of electronic services,
then according to the definitions by the European Commission(archive)
remote software development services do not qualify as an electronic services,
because their delivery is not automated, their delivery involves exhaustive human intervention.