Oct 1, 2026

AI Voice Agent: What It Does and What It Costs (2026)

The phone rings at 7:15pm. Nobody picks up. The caller hangs up and dials the next business on Google.

An AI voice agent fixes that for a fraction of a receptionist’s cost. The real decision is which kind you buy.

The quick answer: An AI voice agent (or AI phone agent) is software that holds a real phone conversation: it answers calls, qualifies callers, books appointments, transfers to a person and calls new leads back. Build-your-own platforms like Vapi, Retell AI and Bland bill per minute and need a developer. Business-ready agents run on your number from day one. For a business, the pick is Carly: it answers when your team can’t, knows the caller from your email and CRM, books them on the right teammate’s real calendar and logs every call in one team inbox.

AI voice agents compared: business-ready vs build-your-own

US list prices from each vendor’s own pricing page, checked October 1, 2026, on monthly billing where there’s a toggle.

AI voice agent	Kind	Price	What you set up yourself
Carly	Business-ready, for teams: calls, texts and email in one inbox	Phone line priced on a short call. Free Zapier-style workflows; AI agents from $35/month	Your instructions and qualifying questions. The Carly team sets up the number with you
Smith.ai AI Receptionist	Business-ready	Free for 25 calls/mo ($3 per call after). Pro $150/mo for 75 calls ($2.50 per call after)	Call instructions, scheduling tool
Rosie	Business-ready	$49/mo for 250 minutes (texts a booking link). $149/mo for 1,000 minutes with calendar booking and live transfers	Business info, FAQs, transfer numbers
Goodcall	Business-ready	$79/mo per agent, 100 unique customers included, $0.50 per customer after	Logic flows, team directory
Vapi	Build your own	$0.05/min hosting, plus transcription, AI model, voice and phone at cost. Vapi’s own calculator puts 1,000 minutes at $82 to $129/mo	Number, prompt, calendar, CRM, transfers, testing
Retell AI	Build your own	$0.07 to $0.31/min, depending on model and voice	Same, with templates to start from
Bland	Build your own	$0.14/min, or $0.12/min plus a $299/mo platform fee	Same
ElevenLabs Agents (ElevenAgents)	Build your own	Free (15 minutes) to $990/mo (12,375 minutes). $0.08 per extra minute, AI model billed on top	Same
Synthflow	Build your own, enterprise	Contracts from $30,000 a year	Scoped with their team

Business-ready agents sell calls, minute bundles or seats with the phone plumbing done. Developer platforms sell minutes and hand you the parts.

What an AI voice agent does on a business line

Under the hood it’s a loop: speech-to-text hears the caller, a language model decides what to say, text-to-speech says it. On a real business line, that loop does five jobs:

Answer inbound calls, around the clock or only when your team doesn’t pick up.
Qualify the caller against your rules: service area, job type, budget, insurance.
Book the appointment on a real calendar while the caller is still on the line.
Route to a person when the caller asks for one or the call needs a human.
Call new leads back within a minute of a web form, before they call a competitor.

Job five is where the money is. In a Harvard Business Review audit of 2,241 US companies, the average response to a web lead took 42 hours. Firms that tried to reach a lead within an hour were nearly seven times as likely to qualify it as firms that waited even one more hour.

An agent that only takes messages handles job one, so compare tools on jobs two through five. Our best AI receptionist guide ranks the answering-first tools, and AI answering service compares them with live operators.

The two kinds of AI voice agent

Build-your-own platforms

Vapi, Retell AI, Bland, ElevenLabs Agents and Synthflow are toolkits for developers, agencies and software companies putting voice inside their own product, and they’re good at it. You pick the model, voice and phone carrier and control every turn. Retell ships templates and simulation testing. Bland folds model, transcription and voice into one per-minute rate.

What you get is an agent with no business attached. Someone still connects the phone numbers, wires in your calendar and CRM, writes and tests the prompt, builds transfers and voicemail, adds consent logic for outbound and keeps it working as models change. With a developer and a product to ship, that’s a fair trade.

Business-ready AI voice agents

Business-ready agents arrive with the plumbing done: they answer your number, read your calendar and take plain-English instructions. Smith.ai, Rosie and Goodcall sit here. What separates them is what the agent knows. Most know your FAQ. Few know the caller: their last email, their open deal, which teammate owns them. That’s the gap Carly closes.

What an AI voice agent costs

Per-minute prices look tiny until you count what surrounds them. Take Whitaker Plumbing: 300 calls a month, about three minutes each, so 900 minutes.

Build your own: $126 a month on Bland’s $0.14 rate, or $63 to $279 on Retell depending on model and voice. Add developer hours, plus limits: Bland’s Start plan caps you at 10 concurrent calls and 100 calls a day, ElevenLabs bills calls over your concurrency limit at double rate ($0.16 a minute), and HIPAA coverage on Vapi is a $2,000/month add-on.
Business-ready, per call: 300 calls a month on Smith.ai’s AI Receptionist is $500.
Business-ready, per minute bundle: Rosie’s $149 plan covers 1,000 minutes.

The minutes are rarely the expensive part. The integrations are, plus someone to fix them when they break.

With Carly, the phone line (Carly Phone) is priced on a short call with the Carly team, scoped to your call volume. Everything else: free Zapier-style workflows; AI agents from $35/month.

Carly: an AI voice agent built for a business

Carly runs your team’s calls, texts and email. The voice agent works because it can see everything else. Here’s a Tuesday-night call to Whitaker Plumbing.

The team rings first. Calls ring Tom and his dispatcher, Megan. In the call flow, “if no one answers” hands the call to Carly. Or let Carly answer 24/7.
Carly knows who’s calling. Claire’s number matches a CRM record and last spring’s email thread about a water heater quote, so the agent starts with context instead of “can I get your name?”
It qualifies her. Tom’s questions run in order: inside the service area? Emergency or routine? For callers who don’t fit, he picks soft or hard disqualification.
It books her. Carly puts Claire on a real Google or Outlook calendar, round robin across the team.
It hands off when it should. If Claire asks for a person, Carly rings the right teammate through ring groups or a phone menu.
Everything lands in one place. The transcript and summary go to the team inbox and Claire’s CRM record. Voicemails are transcribed, and the team is notified of missed calls and voicemails.

You choose the voice (OpenAI or ElevenLabs voices) and edit the instructions yourself. Then call it from your own phone and read the log. The build-and-test tutorial walks through it. It runs on a new number or the one you already have, and the Carly team can set it up with you. Get started with Carly.

Speed to lead on outbound

When a new lead fills in your web form, Carly calls them within about a minute, asks your qualifying questions and books them on the right calendar. See it in the speed-to-lead tutorial, and read AI outbound calling for the consent rules.

Texts from the same number

Texts go out from your business number. Carly answers inbound texts from your knowledge files, qualifies and books. A teammate can take over any thread, and AI answering can be switched off per number. Texts can be scheduled, “STOP” is honored, and carrier registration (toll-free verification or A2P 10DLC) is part of setup.

One team inbox and CRM

Calls, texts and email land in one shared inbox, one timeline per customer. Assign a conversation to a teammate, leave internal comments, @mention each other. A teammate replying by hand pauses the AI on that conversation. Per agent, you choose: send replies, draft them for review, or don’t reply.

The team CRM logs every call, text and email on the person, and writes back to HubSpot, Salesforce and Dynamics 365. Lead routing rules send each new lead to the right teammate. Booking pages with round robin and shared to-dos come with it, and AI email agents can run your support@ address, each with its own address and knowledge files.

Workflows that fire on calls

Workflows trigger on call ended, call summarized, voicemail received and text received. Each carries the outcome (answered, no answer, voicemail), the summary, the transcript, and whether the caller qualified and booked. So “missed call, text the caller back from the business number within seconds” is a workflow you describe once in plain English (more in missed call text back). So is “move the deal stage when the call books.” Carly connects to thousands of apps, so the outcome can go wherever your team works.

What to check before you buy an AI voice agent

Latency. People leave about 208 milliseconds between turns on average, across ten languages (Stivers et al., PNAS, 2009). An agent that pauses a full second before every answer gets talked over. Call it at a busy hour and listen.
Interruptions. Cut it off mid-sentence. A good agent stops and listens. A bad one finishes its script.
Real booking. Does it book on your team’s live calendars, or text a link and hope? On Rosie, calendar booking starts at the $149 plan.
Handoff to a human. A transfer to the right person, not “please leave a message.”
Transcripts and summaries where your team already works, not in a separate dashboard.
CRM logging. Every call on the customer’s record, with the outcome.
Outbound compliance. On February 8, 2024, the FCC’s Declaratory Ruling put AI-generated voices under the TCPA’s “artificial voice” rules. An AI call to a cell phone needs prior express consent, and a sales call needs prior express written consent. Damages run $500 per call, up to $1,500 if willful. In August 2024 the FCC also proposed requiring AI calls to say so at the start. Call people who asked to hear from you, not bought lists. This isn’t legal advice.
Texting registration. If the agent texts, US carriers filter or block business texts from unregistered numbers. Registration should be part of setup, not your homework.

FAQ

What is an AI voice agent?

An AI voice agent is software that holds a spoken phone conversation: it listens, decides what to say from your instructions and data, and replies in a natural voice. Businesses use it to answer, qualify, book, transfer and call leads back. Carly does all of that on your own business number.

Is an AI phone agent the same as an AI voice agent?

Yes. “AI phone agent,” “AI voice agent” and “AI receptionist” describe the same product from different angles. Compare what each one does on the call (answer, qualify, book, transfer, call back), not what it’s called.

How much does an AI voice agent cost?

Build-your-own platforms run about $0.07 to $0.31 a minute as of October 2026, plus a developer’s time. Business-ready agents run from free tiers to a few hundred dollars a month: Smith.ai’s AI Receptionist is $150 for 75 calls, and Rosie is $149 for 1,000 minutes. Carly’s phone line is priced on a short call; get started or book a call from the box near the top of this page.

Is an AI voice agent worth it for a small business?

Usually, if you miss calls or leads wait hours for a callback. Start it on overflow and after hours so your team still takes the calls it can. Carly can pick up only when nobody answers, then book the caller and log the call for the morning. The after-hours answering guide covers that setup.

Can an AI voice agent make outbound calls legally?

Yes, to people who gave consent, such as a lead who just filled in your form asking to be contacted. Since the FCC’s February 2024 ruling, AI voices count as artificial voices under the TCPA, so cold-calling a purchased list is a lawsuit risk. Calling your own web leads, with consent language on the form, is the lower-risk, high-value use.

Can an AI voice agent transfer a call to a real person?

Good ones can. Carly rings the right teammate through ring groups or a phone menu when a caller asks for a person, and a teammate can take over any text thread. Start with Carly and test a transfer from your own phone.

Ready to automate your busywork?

Carly schedules, researches, and briefs you—so you can focus on what matters.

See the prompt

Set up Carly for me. Carly connects to thousands of apps, from Gmail, Outlook and my calendars to Slack, HubSpot and QuickBooks, and keeps working after this chat is closed: answering email, booking meetings, following up and running workflows the moment something happens.

1. Add the Carly MCP server (https://carlyassistant.com/mcp/) and sign me in. Use the one that matches you:
- Claude Code: claude mcp add --transport http --scope user carly https://carlyassistant.com/mcp/ (then I run /mcp, pick carly, and authenticate)
- Codex: codex mcp add carly --url https://carlyassistant.com/mcp/ then codex mcp login carly
- Claude (claude.ai, Claude Desktop, or Cowork): Customize > Connectors > Add custom connector, paste the URL, and sign in. Carly is also in Claude's connector directory at claude.ai/directory/carly.
- ChatGPT: open Plugins, search for "Carly" and add it (or click + and paste the URL), then sign in.
- Cursor: add {"mcpServers": {"carly": {"url": "https://carlyassistant.com/mcp/"}}} to ~/.cursor/mcp.json, then sign in to carly from Customize.
- Muse: I will create a Carly API key at carlyassistant.com/integrations (Advanced > API Keys > Create a new key, with Select all scopes). Build a custom connector to https://carlyassistant.com/mcp/ using an API key as a bearer token, and ask me for the key in your secure credential prompt.
- Grok: go to grok.com/connectors, choose New Connector, then Custom, paste the URL, and sign in.
- Grok Bot: open Plugins, add a custom remote MCP server named carly with the URL, then I approve it and sign in.
- Perplexity: Settings > Connectors > Custom connector > Remote, paste the URL, and sign in.
- Anything else: add a remote MCP server (streamable HTTP) named carly with the URL. It signs in with OAuth.
I sign in with my Carly account, or create one at carlyassistant.com.

2. Walk me through connecting my accounts at https://carlyassistant.com/integrations. Under Accounts, I type each email address I use and click Add Email. On each new address, I click Connect Gmail or Connect Outlook, tick what Carly can reach (Email, Calendar, Contacts, Drive or OneDrive), then click Connect with Google or Connect with Microsoft and grant access. For an address that is already connected, I open Manage access and click Connect next to anything missing. Repeat for every address. Then ask which of my other apps I want connected too.

3. Check it worked: list my connected mailboxes and calendars and tell me every account you can see.

4. Then ask me what to hand off first, for example: "Check all my inboxes for anything that needs a reply today."

See what people say

"Before Carly, I relied on a Calendly link, but the whole process felt impersonal and not very professional. Carly changed that by handling all the back-and-forth, so I'm no longer stuck in endless email threads trying to line up schedules.

Now Carly reaches out to candidates, shares my real-time availability, lets them pick a slot, then sends a Zoom link and drops it straight into my calendar. She sends reminders to both of us before each call, which has significantly reduced no-shows and last-minute confusion.

On top of scheduling, Carly acts like a full executive assistant, sending me my schedule the night before so I can prepare for each call. It reminds me of the old x.ai assistant, but Carly is noticeably smarter, faster, and better suited to my healthcare recruitment business."

Gus Ibrahim, Founder & Director, IHR