If your job board is based in a country within the EU (European Union), and you have entered a VAT number in jobboard.ecommerce.vatnumber, the system will automatically handle EU VAT behaviour.
The user must enter their billing address before the option to purchase credits is available. Once they do, the country is checked, and if it is in the EU, then a VAT number field is presented to them. This is an option field. If not filled, the order will be processed with VAT regardless.
If a VAT number is entered, it will be validated instantly using the EU's online service, and either a green tick or red cross shown next to it.
If the number is invalid, the order can still be completed, but the VAT handling will assume there is no valid EU VAT number.