ElevenLabs Agents vs Twilio ConversationRelay

Choose ElevenLabs Agents or Twilio ConversationRelay for your phone agent. Compare setup work, booking tools, human transfers and the costs you need to budget.

By Morak · Sources and pricing checked October 20, 2026

Start with your current setup

A Twilio phone number can work with either route. Our recommendation depends on who will build and maintain your phone agent: someone configuring it in ElevenLabs, or engineers running the conversation in your application.

You have a Twilio number and need an agent

Evaluate ElevenLabs' native Twilio integration first. You can assign a configured agent to a purchased number without building the conversation server yourself. Plan for someone to configure its answers, connect your business tools and test failed calls.

Your engineers already own the application

Evaluate ConversationRelay first if your team wants to keep the model connection and business decisions in its own code. Twilio supplies the speech interaction; your engineers maintain the conversation application, tool actions and recovery when something fails.

You want a finished business answering service

Start with our AI receptionist shortlist if nobody on your team will own the technical setup. Ask providers to demonstrate your booking and call-transfer workflow, and confirm who maintains it after launch.

Compare AI receptionists

What your team will be responsible for

Scroll the table horizontally to compare both setups.

Responsibilities for ElevenLabs' native Twilio integration and a ConversationRelay application.
Your task	ElevenLabs Agents + native Twilio	Twilio ConversationRelay
Managing the conversation	Configure the agent's instructions, knowledge and tools in ElevenLabs.	Your hosted application connects the model and decides how to respond.
Changing a booking	Configure an API tool and verify that it can safely update your booking system.	Implement the booking API call, permissions and error handling in your application.
Transferring to a person	Configure a transfer through the native integration. The advanced register-call route has a transfer limitation explained below.	Your application routes the call after the Relay session ends and supplies any handoff context.
Keeping custom Twilio routing	Check the native integration's configuration against your existing routing. Advanced registration changes the transfer options.	Your team retains the Twilio call flow and implements what happens before and after the AI conversation.

Example: move a customer's appointment

A caller asks to move tomorrow's appointment to Friday. Both routes need access to the booking system. The difference is where you configure or implement the action; success means the correct booking was saved before the caller hears a confirmation.

ElevenLabs with a Twilio number

Your Twilio number connects the caller to the agent
The agent gathers the details and calls your booking API tool
The booking service returns the saved change or a failure

The tool needs the correct booking identifier, available slots and permission to make the change. Configure how the agent responds when the booking service rejects or delays the request.

ConversationRelay with your application

ConversationRelay sends the caller's speech as text to your application
Your application uses the model and calls the booking API
Your application sends the booking result back for speech generation

Your application manages the model and booking integration. It must handle slow responses, retries and permission checks, then supply an accurate response for Twilio to speak to the caller.

How human transfers work

ElevenLabs: check which Twilio connection you use

ElevenLabs documents call transfers for its native Twilio integration. Its advanced register-call route lets you retain your own Twilio routing, but built-in call transfers are unavailable on that route. Choose the connection before promising a human handoff.

Twilio: your application implements the handoff

Ending a ConversationRelay session returns control to Twilio. Your application can pass context to the next step, then route the call to a person. Passing handoff data alone does not connect the caller to a human; test the routing and unavailable-agent fallback.

What to budget for 1,000 inbound minutes

Use this as a budget worksheet for one month with 1,000 billed AI minutes, 1,000 billed incoming phone minutes and one US local Twilio number. The published charges below cover only part of the cost. Model usage, the connection you choose and implementation work still need an estimate.

Before choosing on price, fill in the variable charges and get an estimate for setup and ongoing support. Existing engineering capacity can change the decision more than the listed service charges.

Scroll the table horizontally to compare both setups.

Budget worksheet for 1,000 inbound minutes, including charges that still need an estimate.
Cost component	ElevenLabs Pro + Twilio	ConversationRelay + your app
Agent service · published component	Pro example: $99/month with 1,238 call minutes. Compare eligible plans before choosing this tier.	$70 for 1,000 Relay minutes at $0.07/minute.
US local phone service · shared assumption	$8.50 for incoming minutes + $1.15 for one number.	$8.50 for incoming minutes + $1.15 for one number.
Language model · estimate separately	Additional usage, based on the selected model and conversations.	Your model provider's usage bill, based on the selected model and conversations.
Connection charges · verify your setup	Confirm the Twilio connection's charges. Media Streams, if used, adds $4.40 for 1,000 streaming minutes at the listed rate.	The Relay charge is listed above. Do not add a separate Media Streams charge without a reason in your architecture.
Hosting and business tools · estimate separately	Any backend or booking service connected to the agent.	Your conversation server plus any backend or booking service.
Setup and ongoing support · request an estimate	Agent configuration, tool integration, call testing and maintenance.	Application development, model and tool integration, call routing, monitoring and maintenance.

USD monthly list prices, checked on the date above. The phone example uses $0.0085 per incoming minute and $1.15 per number. Streaming uses a separate billing clock; the Media Streams example uses $0.0044 per streaming minute and is conditional on that service being used.

Allow for overage, peak simultaneous calls, transfers and extra phone legs where applicable. Outbound and toll-free calls, recording, storage, optional services and taxes can add charges. Confirm actual usage and your plan's terms before committing.

What to test before committing

Use the appointment-change example above as a proposed acceptance test for your shortlist. Keep the script and workload the same, then record successful actions, failed calls, setup effort and billed usage. These checks describe what to test in your own implementation.

Verify the action
Ask for an available appointment, change the time, then inspect the booking system. Count success only when the intended record changed and the agent confirmed the correct result.
Make the tool fail
Return an error or delay from the booking API. Check that the agent explains the failure and avoids claiming success or creating a duplicate booking.
Interrupt and request a person
Interrupt a reply, then ask for a human. Verify the destination, transferred context and fallback when nobody answers.
Compare the full operating cost
Use the same call script and workload. Record billable usage, completed tasks, setup hours and time spent diagnosing failures. Include peak simultaneous calls in the pilot.

Common questions

Can I use ElevenLabs and Twilio together?

Yes. ElevenLabs supports importing a purchased Twilio number for incoming and outgoing agent calls. You do not need ConversationRelay just to connect that number to an ElevenLabs agent.

Does choosing an ElevenLabs voice mean using ElevenLabs Agents?

No. ConversationRelay supports ElevenLabs as a voice provider. Choosing that voice is separate from choosing ElevenLabs' agent builder to manage the conversation.

Can either option connect to my booking system?

ElevenLabs supports tools that call external APIs; with ConversationRelay, your application owns that integration. In either setup, our recommendation is to verify authentication, permissions and the actual saved booking rather than relying on the spoken confirmation.

Sources and pricing references (9)

Official documentation and pricing used for this comparison.

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