According to Austrian law Amazon has an obligation to share the sellers VAT registration number with the Austrian Tax Authority. This has become a requirement especially for amazon sellers that have not yet registered for a VAT number in Austria.
These sellers are in danger of having their account suspended until they become compliant with the Austrian regulations.
As a result, companies selling their products in Austria through Amazon have to upload their registration number on Seller Central.
Source: globalvatcompliance.com
