Since the beginning of this year, the VAT rules on selling digitally to non-registered businesses in the EU have changed. If you sell to the public such things as images or text, photos, e-books, games, web-hosting services, software, website advertising (the list goes on and on) then legally you have to register for VAT in each member state you are selling to. There is no relief for small levels of sales.
Fortunately, the Government has realised what a headache this would be for small businesses. As a result they have created a Mini One Stop Shop (MOSS) with which you can register. You then charge VAT on each sale, report it on a return to MOSS, pay the VAT to MOSS and they then distribute the VAT to each country you have sold to.
However business to business sales will normally be excluded from these procedures if you have evidence ie VAT numbers of the customers. Nor does it apply to products which are not delivered digitally. You need to check on whether or not it applies to you.