Earlier quoted context omitted.
In France it's risky to be self-employed and have only one customer, that could be re-qualified as a disguised employment. I don't know exactly how that works with foreign companies. edit: my remark on foreign company is that, by having no nexus in the country of the consultant, going after them seems difficult
It's similar in The Netherlands. If you are self-employed and have more than one customer it's pretty demonstrable that you are autonomous, can decline work, and the relationship is not solely to avoid an employment contract. Contrary to popular (Dutch) belief, you do not have to have more than one customer... it's just that if you do it can be difficult to prove that you are autonomous. One test is if you are doing…
I actually did this for a while - self-employed in NO, only customer in NL. After a while I had more than one customer, making the issue moot :-)