Are you trying to trace a cell phone number because you need more information about that number? Are you trying to find out who the number belongs to or where they live? If so, you may in fact need a reverse mobile service. These services are used on a daily basis by companies and people just like you and me. They provide you with information about any cell number, land line, or unlisted number.
In order to do a reverse mobile lookup, you will need on that is trustworthy and reliable. Due to the fact that not all directories are the same, if you end up picking the wrong one, you may not find what you are looking for.
So the first thing that you want to look for is if the directory includes cell numbers. To see if they do, it should say it in their terms and services or it will actually have some indication that it does such as the logo or below in the informational text section.
The next thing that you want to look for is if it contains a no hit, not charge policy. Too many directories will make you pay before you even know if you will find what you are looking for. A no hit, no charge policy means that unless the directory has the information, you will not get charged anything.
The last thing that you want to look for is to see if it provides unlimited searches. Just like in a phone book where you can look up any number, a reverse mobile service should allow you to do the same.