There are many reasons why you may need to use a reverse phone number lookup service. Some of the most common reasons are stopping prank callers, checking if your partner is cheating on you, and many more. But what do you need to use a reverse phone number lookup service? And can you perform a search based off a cell phone number?To use one of these services, all you need is the area code and the 7 digit phone number. And yes, many of the better services also have access to cell phone directories where you are likely to find the information you’re looking for.