Identifying an incoming phone number helps protect your privacy and security. Options exist for you to research a partial or whole telephone number, and to ensure that your own information is not released to others without your consent.
Write the phone number down so it is readily available for you to research. If you missed the number when it was initially displayed on your Caller ID screen, scroll through the history to retrieve it. If the call was forwarded to voice mail, the automated system may also have captured the number and will replay it as part of the message, even if the message only contains the sound of the caller hanging up. Certain wireless plans provide a detailed billing option that includes a list of incoming phone numbers during that billing cycle. However, this is not the speediest option.
Examine the phone number for clues as to where the caller may have called from. Pay special attention to the first three digits of the number, which make up the area code, and the next three digits that make up the "exchange." Together, these can reveal the city and state of the caller, and assist you in deciding if you know who the caller might have been. Consult WhereCall.com, txt2day.com or a similar area code and exchange lookup website if these parts of the phone number are not immediately recognisable.
Search for the full phone number online, using "crowdsourcing" websites set up for this purpose, such as WhoCalled.US, PhoneNotes.org or CallRegistry.com. Many websites allow those receiving unknown calls to post the date, time and phone number of the call, along with any supporting information that came across their Caller ID equipment. Often, users post comments and trade advice and information on these websites. This is especially effective if the call originated from a business instead of an individual, since calls from businesses are more likely to have reached a greater number of people, increasing the chances that someone has relevant information to share.
Reverse telephone directories may provide information as to who owns an incoming number. AT&T, for example, offers an online directory assistance page free of charge.
If you decide to call the number to determine who owns it, Consumer Fraud Reporting's website suggests you block your Caller ID information from being transmitted by dialling *67 before the number to preserve your anonymity.