A “no caller ID number” or “anonymous call” conceals the caller’s phone number from the recipient’s caller ID display during a phone call. This is often implemented by entering *67 before dialing the phone number.
No caller ID numbers are used for various reasons, including maintaining privacy, avoiding unwanted marketing calls, or protecting vulnerable individuals, such as domestic violence victims. The technology behind caller ID blocking became widely available in the early 2000s, significantly impacting the telecommunications industry.
