One of the most annoying things in modern times is  getting repeated phone calls from numbers you don’t recognize. Is it a telemarketer? A friend with a new number? That guy/girl you met last week? A collection agency? That’s why so many people try and find out who’s calling them – curiosity and safety are the number one reasons people search for reverse phone lookups.

This guide on reverse phone lookups is part of our series of guides on all topics relating to privacy, searching, and security online.

Table of Contents:

  1. What is a Reverse Phone Lookup
  2. Why Are All These People Searching For Numbers?
  3. How Does it Work
  4. Where do they get the information?
  5. Cell Phone Lookups
  6. Privacy Issues
  7. What If You Can’t Find the Number?



In this guide, we’re going to share with you everything we know about reverse lookups: How they work, what they’re good for, what about cell phones, and a lot more. This guide aims to be the most comprehensive, most accurate online guide about these types of searches.

What is a Reverse Phone Lookup?

It’s another way of saying, get me the NAME of someone from a telephone number. In the olden days (before computers and cell phones), these were published directories similar to phone books, that were primarily used by law enforcement and private investigators. They were also known as cross directories. Like printed phonebooks, these no longer exist, and have mostly moved online.

Why are all these people looking up phone numbers?

There are a number of reasons people look up numbers instead of answering the phone. In our experience, it comes down to three basic human drives: money, love, and fear.

Fear and Anger: Unfortunately, many people get harassed over the phone. Often their tormentors will not bother with private numbers (because people don’t answer these anymore), and instead use just regular phone numbers. In an effort to find out who is tormenting them, the victim needs to find out who owns the number. Once they get the name and address, they can then file a police complaint or other necessary action to get the bully to stop.

Love (or lack thereof): Cheating is probably the number one reason people are looking up numbers. In relationships with a history of mistrust or control issue, one side will often randomly check the phone of the other side. If there’s a pattern of calls to and from unknown numbers, they’ll want to check and see if their partner is cheating on them.

Money:  Mostly this involves people dodging collection agencies and friends/relatives they owe money to. It gets to the point where they can’t answer a call they don’t know the answer to, so they have to lookup the number before answering in.

How Does a Reverse Phone Lookup Work?

There are two parts to how a reverse lookup works, and where the information comes from.

The first part is the information that can be deduced from any phone number, as long as you have a relatively inexpensive up to date database.

That information is:

  1. The city and state of the area code.
  2. The city/location of the first three digits of the phone number.
  3. The original company that provisioned (owns) the phone number.
  4. Whether the phone number is a landline, a cell phone, or serves some other use.
  5. When the phone number first came in to use.

If you’re curious to test this out, you can use the free NPA-NXX search tool provided by Local Calling Guide.

If you want to learn more about how phone numbers in the US and Canada work, we suggest you read Wikipedia’s entry on the North American Numbering Plan.

The second part, the information about the name and address behind the phone number, is more complex. We gave it its own section:

Where does this Data Come from Anyway?

This is a tough question to answer, because it really depends on what type of phone we are talking about.

Let’s distinguish between a land line (the telephone that is hard wired in your house by the telephone company, if you still have one), VOIP (telephones that use internet technology, such as those provided by your cable provider or a company like Vonage) and Cell/Mobile phone numbers.

Historically, names and addresses for land lines were always available. If you remember calling 411 (Directory Assistance), you  provided the name and city for someone, and the operator (later replaced by a robot) gave you the phone numbers it had for that information. So, if you can go one way (name and address to phone), then it’s very easy to go the other way (phone to name and address). That’s where most of the information for Landlines comes from. It is usually provided to companies directly by the carriers. This is the same information provided to Caller ID Companies.

VOIP (Voice Over IP), is the type of technology used by most cable providers to give you phone service. VOIP companies are less integrated with directory assistance. If the VOIP subscriber (the person who bought the phone line from the cable/VOIP company), has asked to enable their caller ID, then there’s a better chance that this information will be publicly available.

Cellular/Mobile phones are the most difficult. There is no directory assistance for cell phones, and so the data has to come from a variety of places. Generally speaking, companies that sell reverse lookups for cell phone data buy this information in bulk from many various sources that have your cell phone number and name.

Can you Really Lookup a Cell Phone Number?

The short answer is, it depends. In our tests, we’ve found that anywhere from 60-80% of cell phone numbers on the various online services will return a match. The longer someone has had a phone number, the stronger the chance that there will be information matching them to their number.

For prepaid phones, the match rate plummets, as these phones can be used almost completely anonymously.

Privacy Concerns

There are two main issues in reverse phone lookup privacy:

  1. Removing your number: You’ll need to contact each and every service online and have them remove your number. This is a difficult job but it’s the only way we know to opt out of these services.
  2. Mobile Apps: There are many mobile apps that claim to provide reverse phone services automatically. Be careful:They will often upload your entire contact directory to their database. That’s how they identify most of the numbers.

What if you can’t get the number online?

If you are being harassed, contact local law enforcement. File a complaint, and see a lawyer about getting a subpoena.

If you need the number for other reasons, and you’re prepared to really pay out for it (usually at least $500, in our research), when we suggest hiring a local private investigator to assist you.