2026-03-10
Caller ID spoofing is the practice of changing the outbound caller ID that appears on the recipient's phone when you make a call. Instead of showing your real number, the recipient sees a number you've chosen.
This is possible because the caller ID system was never designed with authentication in mind. The calling party sets the caller ID value in the SIP INVITE header, and the receiving carrier displays whatever value it receives — unless they have specific filtering in place.
When you place a VoIP call, your SIP client sends an INVITE message to the server. This message contains a "From" header with the caller ID number. The SIP server passes this value through to the terminating carrier, which delivers it to the recipient's phone.
With SpoofGlobal, you set your desired caller ID through the Telegram bot. When your SIP account places a call, the system automatically sets the From header to your chosen number before routing the call to the provider.
The From header in SIP looks like this: From: "Display Name" <sip:15551234567@server>. The number in the SIP URI becomes the caller ID that the recipient sees. CLI (Calling Line Identification) routes are specifically configured to pass this value through to the end carrier without modification.
Not all routes treat caller ID the same way. CLI routes preserve and display your chosen caller ID on the recipient's phone. No CLI routes are cheaper but may show "Unknown", "Private", or a random number instead of your chosen caller ID.
The choice between CLI and No CLI depends on your use case. If you need the recipient to see a specific number — for callbacks, brand recognition, or verification — you need a CLI route.
Caller ID spoofing itself is legal in most countries. However, using it for fraud, impersonation of law enforcement, or harassment is illegal. Always use it responsibly.
Yes, caller ID spoofing works on landlines, mobile phones, and VoIP phones. The recipient sees whatever number you set, regardless of their phone type.
The call still routes through carriers that maintain records. While the recipient sees your chosen number, the actual call path is logged by the carriers involved.
CLI routes display your chosen caller ID on the recipient phone. No CLI routes are cheaper but may show Unknown or a random number instead.