A Nextiva AI receptionist through call forwarding
Forward a Nextiva user's calls to a Cartesia agent's number, and the agent answers as your Nextiva AI receptionist and hands callers back to your team.
Front-line agent
Answers forwarded calls and passes the rest to your team.
Instructions
Answer office hours, accepted insurance and directions. Transfer billing questions to the billing call group, booking to the front desk, and named requests to that dentist's line.
- Handoff
- Nextiva team number
Connected tools
- Transfer to NextivaTransfer
What a Nextiva AI voice agent can do
Open one to watch a call. The grey lines are the tools the agent calls mid-sentence.
Call forwarding always on a Nextiva user sends every direct call for that user to the agent's number until you turn it off.
The agent answers what patients ask most, such as Saturday hours and accepted insurance, and ends the call without a transfer.
Patients who need a person go to a Nextiva number, such as a call group, a call center or another user.
Nextiva settings
These are the voice portal settings for forwarding one user's calls.
- Where
- Voice portal, Users, the user's menu, Voice Settings, Forwarding.
- Rule
- Call forwarding (always), set to the Cartesia agent's phone number and switched on.
- Who
- An administrator signs in to the voice portal to change it.
- From the phone
- Dial
*72, the number and#to turn it on. Dial*73to turn it off.
Set it up
A phone hand-off by call forwarding. There is no SIP trunk between Nextiva and Cartesia and no native Nextiva integration. Vendor details read in November 2026.
Give the agent a number
Import a number from Twilio or connect a SIP trunk number. Transfers work only on Twilio and SIP trunk numbers, not on Cartesia numbers.
Forward a Nextiva user's calls
In the Nextiva voice portal, open Users, open the user's menu and choose Voice Settings, then Forwarding. Expand Call forwarding (always), enter the agent's number, save, and switch it on.
Set the way back
Add a transfer rule in Cartesia to a Nextiva number that reaches the right person or group, not the forwarded user's own number.
Test both directions
Call the forwarded Nextiva number, reach the agent, and ask for a person to check the transfer back.
Before you build
Only direct calls forward
Call forwarding always moves calls dialed to the user. Calls handed to that user by a call center or call group don't forward, so give the agent its own user.
Selective forwarding comes first
Nextiva applies Call forwarding selective before Call forwarding always. Check the user has no selective rule that catches calls meant for the agent.
Staff can switch it from a handset
The *72 and *73 feature codes turn forwarding on and off from the user's phone, so the front desk can take the line back without the portal.
Transfers are cold
The person who picks up gets the call, not the conversation. Have the agent tell the caller where it's sending them before it transfers.
Use cases for teams on Nextiva
More integrations
Enterprise-grade security
HIPAA compliant
SOC 2 Type 2
GDPR
Nextiva AI voice agent FAQs
Does Nextiva have an AI receptionist?
Yes. Nextiva's XBert AI receptionist greets callers, books appointments and captures leads. To use a Cartesia agent instead, forward a Nextiva user's calls to the agent's phone number. Nextiva has no built-in Cartesia connection, so the agent only sees calls you forward.
Can I use my own AI agent with Nextiva?
Yes, if the agent has its own phone number. Call forwarding (always) on a Nextiva user sends calls there, and the agent transfers back to a Nextiva number for the right person or group. A Cartesia agent calls webhook tools you define in your own systems and uses the voice and model you choose.
How do I forward Nextiva calls to an AI agent?
In the voice portal, open Users, open the user's menu and choose Voice Settings, then Forwarding. Expand Call forwarding (always), enter the agent's number, save, and switch it on. From the user's phone, *72 plus the number and # turns it on, and *73 turns it off.
Can the agent answer calls to a Nextiva call group?
Not through a user's forwarding, which skips calls a call group or call center hands out. Point a number at a user reserved for the agent and forward that user.
Why aren't my Nextiva calls reaching the agent?
Check for a selective rule first. Nextiva applies Call forwarding selective before Call forwarding always, so a selective rule can catch calls meant for the agent. Also check that callers dial the user directly, since group calls don't forward.
Who bills the minutes when Nextiva forwards to an agent?
Cartesia charges $0.03/min, plus LLM usage and telephony, and Twilio or your SIP carrier bills the agent's number. Transfers work only on Twilio and SIP trunk numbers, not on Cartesia numbers.
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