Calling Line Identification (CLI) Explained

Calling line identification, or CLI, is the caller ID data that shows the caller's number on your phone. Here is how it works, and how to show or hide yours.

Terms you may see

How it works

When you call, your network sends your number along with the call. The other person's network passes it to their phone, which shows it, or shows the name from their contacts. If you restrict your CLI, they see "Private" or "No caller ID".

Hiding your number

• One call: dial a prefix before the number, such as *67 in the US or 141 in the UK.
• All calls: turn off "Show my caller ID" in your phone's call settings, if your carrier allows it.

Emergency services can usually see your number even when hidden.

Why CLI can be wrong

CLI can be faked by callers who control their phone system, which is called spoofing. Some countries require networks to check caller ID to cut spoofing, but it still happens, especially on international calls. See caller ID spoofing.

Business lines

Companies often show a main number instead of each phone's own line. That is normal and allowed, as long as the number belongs to them.

CLI and verification calls

Apps that send codes by voice call usually call from changing numbers. Do not call those numbers back; just type the code. See finding your code.

Caller ID on landlines and VoIP

Landlines show caller ID only if the line and phone support it, which sometimes costs extra. VoIP services, such as internet phone lines, send caller ID from their system and let you choose which number to show, as long as it is one you are allowed to use.

FAQ

What is calling line identification?

The caller ID number sent with a phone call.

How do I hide my number on a call?

Use your country's prefix, such as *67 in the US, or change caller ID settings.

Can caller ID be fake?

Yes, through spoofing. Call back on an official number if unsure.

Related: caller ID spoofing · private numbers · phone extensions.