How to Change Your Caller ID (CLI) on a SIP Trunk

When you place a call through VoxioTelecom, the number shown on the called party''s phone is not controlled by us. It is the Caller ID (CLI) your softphone, PBX or softswitch sends inside the SIP header. This guide shows exactly how to set that number, on every common setup.

Where the caller ID actually comes from

Wholesale voice providers deliver calls; they do not invent a caller ID for you. We pass the CLI you send straight to the destination network. To display +441234567890, your device or PBX must send that number in the SIP From field and, ideally, in P-Asserted-Identity as well.

There is no "set my caller ID" button in the VoxioTelecom portal — the CLI lives in your signalling.

How to set the caller ID in PhonerLite (manual dialling)

For manual dialling we recommend PhonerLite, a free, lightweight SIP softphone for Windows.

1. Download and install PhonerLite.
2. Create a new SIP account with your VoxioTelecom trunk credentials.
3. Open the account settings.
4. In the Caller ID / From user field, enter the number you want to present in E.164 format (for example 491511234567).
5. Save and restart the softphone.
6. Dial your destination, adding the tech prefix if you are using a premium CLI route.

If that field is left blank, many networks reject the call or display "anonymous".

How to set the caller ID on FreePBX, 3CX and other PBXs

On a PBX the CLI is normally set on the extension, the outbound route or the trunk:

• FreePBX — set Outbound CID on the extension or the outbound route: +441234567890 or Your Name <+441234567890>.
• 3CX — set Outbound Caller ID on the extension or in the outbound rules.
• Asterisk / FreeSWITCH / other — send a valid From header and a matching P-Asserted-Identity.

Always keep the number in international E.164 format: no leading zeros, no spaces, no letters.

Premium CLI routes: using the tech prefix

Many premium routes need a tech prefix so the CLI is guaranteed end to end:

• Germany premium CLI — dial 1112 + 49 + the number, e.g. 11124915151234567.
• Check the exact prefix for every destination in the Rates tab of your portal.

Common caller ID mistakes

• Expecting the portal to set it — the CLI is only read from your SIP header.
• National format — do not send 0151…; send +49151… or 49151….
• Sending a name instead of a number — most carriers require a numeric CLI and strip display names.
• Anonymous or empty From user — this is frequently rejected on premium routes.

How to test your caller ID in 4 steps

1. Configure the CLI as described above.
2. Call a mobile or landline you can answer yourself.
3. Check the number that appears on the handset.
4. If it is wrong or shows "unknown", inspect the From header in your SIP trace.

Need help with CLI delivery?

If you are unsure whether your caller ID reaches us correctly, open a support ticket or use the live chat. We can read the SIP headers on our side and tell you exactly what we receive.