### Answer To add your existing Twilio number to Retell, you'll need to set up Elastic SIP Trunking and then import the number. ## Steps: 1. Create Elastic SIP Trunking in Twilio [(1) ]() - Create a trunk and configure termination (for outbound) — note the termination SIP URI - Setup origination (for inbound) using Retell's SIP server:

sip:sip.retellai.com

- For termination, either whitelist IP addresses or create auth with username/password 2. Move your number to the Elastic SIP Trunk 3. Import the number to Retell - Supply the termination SIP URI from Step 1 - If using credential auth, provide the username and password - You can import via the dashboard or programmatically using the [Import Number API]() [(2) ]() Once imported, your number will appear in your Retell dashboard and work like any Retell-purchased number for inbound and outbound calls. [(1) ]() Common Issue: If inbound works but outbound doesn't, check that your Termination SIP URI has no spaces and use a localized termination URI near your region. Also verify your credentials are correct (note: username differs from friendly name) .

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Twilio](https://docs.retellai.com/deploy/twilio) [[2] Import Phone Number](https://docs.retellai.com/api-references/import-phone-number) ​

Thanks for the feedback, glad I was helpful.