This is not easy in practice. In the Netherlands we are dealing with the Personal Data Protection Act and a phone just is basically private. But many people make their phone known by them, for example on a website.
5 Tips to 06 numbers to trace
Finding someone's 06-number:
1. Search by http://www.06gids.nl/ or http://www.yournumber.nl/. These are online directories which people their name with phone number to register. Only if someone has registered itself you his or her 06 number found herein. That chance is not very large, because most people do not register. It is also a good chance that the information is out of date. Many people change their telephone number. But you never know.
2. Search the Internet. If someone's name, do you go googling. Some people put their 06-track at the 'basic information' on their Facebook profile. Others find on Linkedinn. Perhaps you will find there a (company) number as that person a private company. If you possibly another way to contact someone you can send a message on Twitter, Facebook or any other social media.
Finding the correct name and address to an unknown 06-number:
3. sometimes it can be very simple. Type the 06-number in the search bar of Google and sometimes appears immediately a match. This is especially the case for companies or stores that you called.
4. Put on your own phone number recognition, call them the number back and see who answers.
5. You can try to find out who's calling on http://www.omgekeerdzoeken.nl or http://www.spyderweb.nl/. Sometimes it works.
It is virtually impossible for individuals to find out who is calling with an "unknown number". The caller in this case the caller ID on his phone turned off. Only the provider can figure this out. For example if you are being harassed by phone and you do not know who it is, you can report it to your provider. They can the person initially send an alert. If that does not help then you can block the number. You will have no more trouble from unwanted calls. It is best to simply ignore these calls. After a while it stops usually self.