When it comes to the VAT registration in a specific country, there are two options for a registration:
You start selling goods once your VAT registration has been completed - a regular VAT registration
You have already started selling goods and need to register from a date in the past. This is called a backdated registration.
Depending on the country there might be different conditions, when it comes to a backdated registration. Please see a list of the countries with their requirements below.