We were really hoping to migrate our Retell phone numbers over to our own twilio account. Would that be possible?
For more context:
We currently use a custom LLM in conjuction with the Retell infra to control our agents. We want to move to Twilio to use the same phone number in other use cases (beyond just handling our calls - ex: SMSing). Maintaining the same phone number is crucial for our user experience as we make this migration. Is there anyway to just move the phone number into our twilio account so that we can control the SIP trunks/SMS config/campaigns etc. while retaining our use with Retell (We are more than happy to put in the work to do the manual SIP trunking with Retell instead of our current OOTB functionality).
Based on the available documentation, you cannot directly transfer ownership of Retell-purchased phone numbers to your own Twilio account(1). However, you can achieve your goal through an alternative approach.
Recommended Solution: Purchase a New Twilio Number and Connect via SIP Trunking
Since maintaining the same phone number is crucial for your user experience, here’s what you can do:
Purchase a new number directly from your Twilio account (or port your desired number to Twilio if you own it)
Set up Elastic SIP Trunking in Twilio to connect that number to Retell AI(2)(3)(4)
Import the Twilio number into Retell using the custom telephony integration(2)
This approach gives you full control over the number in Twilio for SMS, campaigns, and other use cases, while still using it with Retell AI agents for voice calls(2)(4).
Setup Process
With Elastic SIP Trunking, you’ll configure:
Termination settings in Twilio for outbound calls(2)
Origination settings pointing to Retell’s SIP server (sip:sip.retellai.com)(2)
Import the number into Retell with your termination URI(4)
When using this method, all telephony functionalities supported by Retell numbers will also be supported, assuming your telephony provider supports them(2).
SMS Capabilities
For SMS functionality with Twilio numbers connected to Retell, SMS capabilities are available for your own Twilio numbers(5). You’ll manage SMS configuration, campaigns, and compliance directly through your Twilio account while maintaining voice call integration with Retell(5).
Please give me a human response with someone that could potentially actually help me migrate the phone number to our twilio account… Twilio allows this to occur: Twilio Help Center