Laws and regulations
To work as a sole trader in the Netherlands you must first have a legal right to reside in the country. For people with EU/EER/Swiss nationality this means registration at the Immigration and Naturalisation Department (IND) as a sole trader. People of a different nationality must request a residence permit to work as a sole trader.
Permits and diplomas
You no longer need any permits or diplomas for compulsory Chamber of Commerce registration. That is not to say that you can simply get started on any business you want in the Netherlands. For some business activities there are clear sector-specific regulations. For instance, if you start a taxi company, a permit is necessary from the Transport and Water Management inspectorate or if you begin a restaurant, then you will have to contact the municipal authorities where you are located for the necessary permits.
Links to interesting websites
Information about entry into the Netherlands
Information on the value of foreign diplomas
Answers for business
The Tax Office
Nuffic is part of the Dutch higher education establishment