Caller ID spoofing is similar to text message spoofing in that a caller chooses the information displayed on the recipients caller ID for a land line phone or cell or PDA.

The specified incoming caller ID information can be numbers or letters. For example the sender could specify that the recipient's caller ID shows the incoming call is from "411" or from the "Internal Revenue Service."

Historically, telemarketers, private investigators, law enforcement agencies and collection agencies have used caller ID spoofing to present the call recipient with a specific desirable phone number or name. These entities accomplished this through one of a handful of "special" services offered by telephone companies (e.g., VOIP - Voice Over Internet Protocol is the technology used by Vonage to make internet phone calls ).

Today caller ID spoofing is readily available to the public. It can be accomplished through the use of commercial services selling pre-paid calling cards. Users visit a caller ID spoofing web site and purchase the desired amount of minutes. An actual calling card may be mailed to the customer (if the customer chooses) but is typically not involved. The spoofing service just keeps track of its customer's available minutes. Spoofing services charge roughly between $.10 and $.17 per minute.

The caller ID spoofing services initiate a call either through the use of a web site or a specified call in phone number. In either case the spoofer initiating the call contacts the spoof service and enters their PIN number. The spoofer enters the number they wish to call and then the information they wish to be displayed on the caller ID of the recipient. The caller also might have the option (depending on the caller ID spoofing service) to change their voice and record the call for later review. Finally the spoofed caller ID data is sent. The spoofer and the number called are then connected by the spoof service (known as bridging).

Some commercial caller ID spoofing service providers:

SpoofCard
SpoofTel
TeleSpoof
SpoofCom

Another service called AfterVoice allows the user to choose one of eleven voices (male or female of varying national origin) to read a typed message to the recipient. The service will call the specified recipient with spoofed caller ID information and the chosen voice will speak the message the sender has typed. The service does add a note at the end of the message stating that the call is a demo and allows the recipient to remove their number.

External links:
Kunoichi.info