How to Import a Twilio Phone Number for AI Calling

Importing your own number works with any third-party telephony provider that supports Elastic SIP Trunking — this guide uses Twilio as the example, but the same steps apply to other providers with the same capability. Elastic SIP Trunking is what connects your VoIP setup to the phone network (PSTN) so your AI assistant can make and receive real calls.

Before you start

You’ll need a Twilio account (or another elastic-SIP-trunking-capable provider) and a phone number to import or purchase through it.

Part 1: Set up the SIP trunk in Twilio

1. Go to console.twilio.com, click Explore products, then Super Network, then Elastic SIP Trunking.

2. From the Elastic SIP Trunking Dashboard, click Get Started, then Create a SIP Trunk, and give it a name (for example, “AI Calling”).

3. Configure general settings: enable Call Recording (record from ringing) and Call Transfer (SIP REFER), set the Caller ID for the Transfer Target to the caller ID as transferee, then save.

4. Set up Termination (for outbound calls): click Termination in the left navigation and note the Termination SIP URI shown — you’ll need this later.

5. Whitelist IP addresses. Since the SIP server doesn’t use a static IP, whitelist the full range: under Authentication, click + next to IP Access Control Lists, and create two lists:

   • Friendly name default ACL 1, address 0.0.0.0/1
   • Friendly name default ACL 2, address 128.0.0.0/1

   Save.

6. Set up Origination (for inbound calls): click Origination, underneath Termination, and add a new Origination URI: sip:ecabe71af1354f858dc49374b8293591.sip.telnyx.com

7. Add a number to the trunk. In the top right, click Add a Number and either buy a new number or add an existing one — even a purchased number still needs to be explicitly added to the trunk. Note the number in raw format (+country code, then the number, no spaces or special characters) along with your Termination URI.

Part 2: Import the number into Assistantz.ai

1. In your AI portal, go to the number tab — either in the main navigation or inside an assistant — and click Import a Number.
2. Enter the raw-formatted number and your Termination URI, then click Import.
3. Sync the number with your assistant to start making outbound calls and receiving inbound calls. Your Termination URI is saved automatically, so you won’t need to re-enter it on future imports.

Debugging

If inbound or outbound calling isn’t working after import, check the logs in your telephony provider’s console (Twilio logs, for Twilio) — Assistantz.ai has no visibility into why a carrier rejects a SIP packet. Common causes: an unverified account, a non-raw-formatted number, or country-specific regulatory requirements. Your telephony provider’s support is the right place to debug carrier-side rejections.

Next step

Once your number is imported and synced, continue to how to deploy an inbound and outbound AI call assistant.