This does not constitute professional tax advice. We strongly advise consulting a tax specialist to find out your specific obligations.
To register for a VAT ID, you'll need to provide specific documents to the State Revenue Service of the country in which you're registering. In most cases, you'll be asked to fill in a registration application and provide the following information:
Legal entity information (registration ID, legal name, legal address) and contact info
Personal information (personal ID, date of birth, name and surname, place of residence)
Description of business activity you are performing
Your bank account details
Other questions may apply (eg. business partners' information, computer accounting information, core capital information, etc.)