Here is the reply I got from them: (My accountant approves)
Hi Zhivko,
My name is Rob, thank you for taking the time to contact Envato Market Help.
Our VAT number is EU826409867. VAT numbers issued to international companies like Envato (Australia) with an EU prefix cannot be checked against the http://ec.europa.eu/ database. To verify the VAT number, you’ll need to contact the Tax Authority where our VAT Moss is located. Which is HMRC in the United Kingdom.
More information:
https://www.gov.uk/guidance/register-and-use-the-vat-mini-one-stop-shop
Robert B
Envato Market Help Team