If you don't know how to look up an unlisted number then just read the article carefully, you should be able to get what you are looking for.
Here is how to do it: First and foremost you are going to ask your self this question: How badly do I need the details behind this unlisted number? From the answer, you can then be able to decide if you are going to use a paid service or free service.
The reason this point came up is because if the number is not so important to you or maybe you just want to do it for the fun, then you can just use any of the free services out there.
A simple 'free reverse phone look up service' search on Google should give you a handful of resources to try your hands out on.
However if the number is very important to you, you wouldn't want to waste your time going to the free services.
This is because you will end up burning out your time for nothing and at the end of the day you will still have to go back to a paid service.
A paid service usually gives great value for money.
This is because you don't even spend up to a quarter of what you are going to pay a private detective to help you with an unlisted number look up service but you will end up getting the same thing that he or she would have given and who knows you may even get a lot more depending on the service you are using.
To be able to get the best results always use a service that is highly recommended and one that the database is usually updated regularly.
This will always make you get top notch information for which ever number it is you are running the search on.
The details you can expect to get when you look up unlisted phone numbers include: name of the person, present and past address, employment records, family history etc.
However always make sure you are using a good reverse phone look up service or else you won't be able to get what you want