3CX v20 Cloud & Twilio E.164 Formatting - No Outbound Calls

[Eastcott]

Issue:

• Outbound calls from 3CX v20 Cloud to Twilio are failing with error 32101: The called number is not correctly formatted.
• Twilio requires all called numbers to be in E.164 format (e.g., +13052225000).
• Even when dialing with the + and configuring outbound rules to prepend +, Twilio receives the number without the plus sign (e.g.,13052225000).

Troubleshooting Steps Taken:

• Outbound rules have been set to prepend + and country code.
• Attempted dialing with explicit E.164 format from endpoints.
• Verified all available number formatting options in the 3CX v20 Cloud interface.
• Confirmed that the “Outbound Parameters” tab and SIP header manipulation are not available in 3CX v20 Cloud.

Findings:

• 3CX v20 Cloud does not expose SIP header or outbound parameter controls to end users.
• Number formatting is handled internally by 3CX, and the platform appears to strip or ignore the + before sending to Twilio.
• There is no way for the user to force E.164 formatting with a plus sign from the current web interface.

Next Steps Requested:

• Need 3CX support to advise on how to ensure outbound numbers are sent to Twilio in E.164 format (with the +).
• If this is a platform limitation to allow E.164 formatting for SIP trunks?

 

[mattwarner]

Did you ever receive assistance with this question? I am having the same issue presently.

 

[CXBridge Ops]

One question, which Twilio template are you using? There are two available templates: Twilio (Auto-setup) and Twilio.

For some reason, only the Twilio template works for me. I didn’t make any modifications, and it works correctly. For example:

 

[mattwarner]

I currently have it on Twilio Auto. When I had it on Twilio, SMS/MMS didn't connect. Is that your only rule? The instructions left me with the impression I needed a rule for each potential number of entered or call destination. Do I just need one? And do I need to do anything with the E.164 screen? There seems to be a lot of opportunity for configuration conflict in this process, especially on hosted implementations.

 

[CXBridge Ops]

@mattwarner

I only have one rule configured, and it works correctly. If I need to call a new country, I simply add its country code under “Calls to numbers starting with prefix” and enable that country in Twilio, including both low-risk and high-risk numbers.

There is no need to create a separate rule for each country unless you want to use a different Outbound Caller ID for each one.

Please configure the rules as I have done and test again. If you encounter an error, check the call report in the Twilio console (call report) for more details.