do they handle sales taxes? for in country vs out of country sales?
Companies pay sales tax to the state and can deduct sales tax they paid to other companies.
There are rules for applying sales taxes to other EU countries and it get's complicated fast; once you do more than X amount in another EU country, you're supposed to register in that country and file taxes in that country. Thresholds here: https://ec.europa.eu/taxation_customs/sites/taxation/files/r...