Those who have access to the Dutch labour market are allowed to work for a Dutch employer. That is anyone with a passport from one of the countries of the European Economic Area, excluding Croatia; or with a Swiss passport.
Those who do not have access to the Dutch labour market can obtain a work permit or a 'No employment restrictions' (Arbeid vrij toegestaan) endorsement.
If an employer is found to have foreign workers working for them illegally, the Netherlands Labour Authority will impose fines (Dutch).
More information about rights and obligations can be found at workinnl.nl.
Notification portal
More information about the notification portal can be found at postedworkers.nl.
British employers (and workers) in the Netherlands and Dutch nationals working in the United Kingdom (UK) have to take into account a number of rules after Brexit. More information can be found at rvo.nl (Dutch).