PhoneSeek.info will let you know in most cases.
There are several "reverse lookup" sites that can be used for this. I love reverse phone directory. You will be hard pressed to be able to get this without paying a small fee, however.
An individual can find a phone number using a reverse directory by inputting the phone number in the space provided in the reverse directory and pressing enter. This will produce the desired results if the phone number is not an unlisted number.
Yellow Pages, White Pages, and 411 offer free cell phone directory online. Of course there are other sites that give you free reverse look up as well.
There is no such thing as a free cell phone directory right now
One can find a free directory online at Keetro or Directory Free. The website AnyWho has a free white pages directory where one can look someone up by name address or phone number.
There is no such thing as a free reverse cell phone directory, however, this site offers the best and cheapest service. http://www.squidoo.com/reverse_cell_lookup
There are free "reverse directory" websites for many countries, and also reverse look-up sites that charge money. However, many numbers, most especially mobile phone numbers, are not listed at all in any public directory.
The Reverse Telephone Directory is an Australian Phone Look up service. This service is free to use and can find Listed and Unlisted numbers from Mobiles or landlines in Australia. It is generally used to identify an Unknown number one has received a Missed call from.
There are websites that offer "reverse directory" capabilities, meaning that you enter the telephone number and get back the name of the person or business.
With cell phones, it is difficult to track the numbers. I have researched this topic and found a few sites for reverse look up where I entered a cell phone number to see who it belonged to, and none of the sites provided me with the correct answer. Although I do believe this option will be available in the future, I was not able to find this service for free online. The site "free-reverse-cell-phone-directory" does offer a premium version where you are required to pay for the information.
The white pages provides you will numerous ways to contact people. You can find them from a name, a business, an address and you can even reverse phone numbers.
The WhitePages websites offer a free to use reverse phone number lookup. By entering a phone number, one can find out who just called or texted his/her phone.