In hindsight, no call is untraceable in the post 9/11 era. However, you can still try your luck by masking your number by dialing *67 before you place a call. Your number will not show on the receiver’s caller ID. This is just the starting point but ultimately you can be caught or your number can be easily identified by the recipient through Automatic Number Notification ( ANI) or by dialing *57, commonly used by 911. If you want to play a prank on someone, you can use this method when calling from a public pay phone.
Obtain call blockers. This can be an efficient way of stopping the recipient from tracing your call. You will install this on your computer, with the encrypted codes disappearing immediately after you hang up. However, the device is not easily available in the market as it is considered unsafe for personal possession or use. Nonetheless, you can get a hold of it through an online purchase.
Spoof card – if possible obtain a spoofing service which allows you to make anonymous calls. The drawback again is that they are not common for personal use, despite high demand. Most Private Investigation companies use spoofing services, along with law enforcement agencies. The basic purpose of a spoof card is to the change the information visible to the recipient. You will make a call from a certain number but the caller ID will display a different number, ultimately keeping your anonymous presence intact. Most calling companies provide the service.
Soft phone option can be exercised in order to make untraceable calls. The software uses internet and a proxy server to dial through, making you out of reach of ANI and *57. However, it is also not a fool proof method as the Internet Service Provider can easily identify the exact location from where the call was made.