There is no conspiracy, just a misunderstanding between legal systems and an apparent unwillingness to resolve the issue. Generally, it is not a problem for a Canadian or a US Citizen to come to Europe to perform a service for a few days which he invoices from the US. In Germany, the rule is that he must not spend more than 6 months in Germany lest he falls under German employment law (and needs a work permit etc). It is not a problem as an American to enter Germany, conduct a trainings class (that is not offered by anyone else anywhere), and leave three days later. Also, as far as I am informed, had the agreement for payment been signed by my current full-time employer (a German company), the entire thing would have been no problem -- it is legitimate for a German company to send an employee abroad to conduct a trainings class. The agreement was signed by me though, several years ago. Under German tax law, there's a special status for certain specialized tasks (amongst others, specialized teachings) that allows one to act in some aspects like a 1-person-company. Think of this as a more restricted form of freelancing (e.g. you can't just decide to have said status if you're a programmer, you have to qualify for it due to the specializedness of whatever it is that you're doing). The issue now is that today's custom agent did not treat this any different from a regular Joe trying to get into the US for a full-time job. Which this isn't. It's more that someone 'specialized' is contracted in from abroad for two days to provide expertise not available locally. I hope this clarifies the situation a bit.