1. Create or select the Sipflex profile
- Sign in to the Sipflex portal and open Voice → Profiles.
- If all account numbers should route to ElevenLabs, edit the default profile. Otherwise create a new profile and give it a clear name.
- Select Eleven Labs AI as the connection type.
- The inbound SIP URI and number format are filled by the template. Review the profile and save it.
- If you created a separate profile, assign the required numbers to it in the number or Line Manager area and save the changes.
2. Create the ElevenLabs agent
Create and configure the conversational agent in ElevenLabs. Sipflex does not create the agent or control its prompt, tools, voice or workflow. When the agent is ready, open the ElevenLabs phone-number area and choose Import Number → From SIP Trunk.
3. Enter the inbound configuration
| ElevenLabs inbound field | Value |
|---|---|
| Label | Any clear label, such as Sipflex |
| Phone number | The Sipflex number in E.164 format, for example +442034567890 |
| Media Encryption | Allowed or Disabled |
| Allowed Numbers | Add other numbers only when required |
| Remote Domains | Leave empty |
| Authentication username | Leave empty for inbound |
| Authentication password | Leave empty for inbound |
Do not enter a username or password in the ElevenLabs inbound configuration. The Sipflex template routes the incoming call to ElevenLabs; this is not an inbound registration login.
4. Enter the outbound configuration
| ElevenLabs outbound field | Value |
|---|---|
| Termination URI | sip.sipflex.co.uk |
| Transport | TCP |
| Media Encryption | Disabled |
| SIP Trunk Username | The Sipflex phone number or username exactly as displayed in the portal |
| SIP Trunk Password | The separate Sipflex trunk password |
The imported phone number uses E.164, such as +442034567890. The SIP trunk username must remain exactly as shown in Sipflex, even when that format differs.
5. Optional TLS transport
To use TLS signalling, set the termination URI to sip:sip.sipflex.co.uk:5061;transport=tls and select TLS as the transport in ElevenLabs. Configure media encryption consistently on both sides if you deliberately enable SRTP.
6. Blind transfer using SIP REFER
When an ElevenLabs tool performs an immediate transfer using REFER, set its destination type to SIP URI. Use the destination in this form:
sip:DESTINATION_NUMBER@sip.sipflex.co.ukUse the destination-number format accepted by your Sipflex account and test transfers independently from ordinary inbound and outbound calls.
7. Save and test
- Import the number in ElevenLabs and associate it with the intended agent.
- Call the Sipflex number from another network and confirm the agent answers.
- Verify two-way audio.
- Test outbound calling separately if it is enabled.
- Test REFER transfer with a controlled destination if the workflow uses it.
Third-party interfaces change over time. If an ElevenLabs label differs, use its current SIP-trunk documentation while preserving the Sipflex values described here.