An AI voice agent answers or makes phone calls and holds the conversation itself, in a natural voice, without a person on the line. In 2026 it books appointments for dentists, calls web leads for sales teams and phones shoppers who leave a checkout. This guide explains how one works, the jobs it does, whether to buy one ready-made or build one on a platform, and what each path costs, with prices from the vendors' own pages checked 9 October 2026. Our other guides compare the tools for each job in detail.
Some vendors on this page, Outcraft AI among them, pay us a commission if you sign up through our links. It doesn't change which tools we list or what we say about them. How we compare.
What an AI voice agent is
Three pieces, running in a loop many times a second. The agent listens: speech-to-text turns what the caller says into words. It thinks: a language model reads those words together with your instructions (what the business does, what to ask, when to transfer), your knowledge (prices, hours, policies) and its tools (a calendar to book into, a CRM to look up an order, a phone system to transfer the call). Then it speaks: text-to-speech turns the answer into a voice. Platforms price the three pieces separately: on Vapi, for example, the transcriber costs about a cent a minute, the model about a cent to four and a half cents, and the voice one and a half to two and a half cents, on top of Vapi's own five cents (Vapi). Some engines now do the listening and speaking in one step, which Retell sells as its voice infrastructure at $0.055 a minute (Retell).
The call itself travels over an ordinary phone line, bought from a carrier such as Twilio or Telnyx or supplied by the platform. That is why every price on this page has a phone-line charge somewhere in it.
What an AI voice agent is not: a phone menu (“press 1 for sales”), a recorded message, or a chat widget. It talks back, it can be interrupted, and it can do things during the call. A ready-made AI receptionist or AI sales agent is an AI voice agent that someone has already built for one job.
The jobs AI voice agents do
| Job | What the agent does | Our guide |
|---|---|---|
| Answering the phone | Greets callers, answers questions, books appointments, takes messages, transfers the calls that need a person | Best AI answering services, and the guides for dentists, law firms, HVAC, plumbers and restaurants |
| Store support | Where is my order, returns, exchanges, stock questions, with the caller's order history in front of it | AI voice agents for ecommerce |
| Calling new leads | Phones a web lead within minutes, qualifies and books the meeting | Speed to lead and AI sales agents |
| Calling shoppers | Phones a shopper who abandoned checkout, answers what stopped them, texts a link to finish | AI abandoned cart recovery calls |
| Keeping customers | Calls subscribers whose payment failed, customers who click cancel, trial users who stall | Failed payment recovery calls |
| Calling you | Google's, Meta's and other assistants now phone businesses on their users' behalf to check prices and book | When the caller is an AI |
Buy one ready-made or build one on a platform
There are two ways to get an AI voice agent, and the price tags are not comparable until you add your own time to the second one.
| Ready-made service | Build on a platform | |
|---|---|---|
| What you get | An agent already built for one job, with the booking, transfer and CRM connections done; a web page to set your details; support | The engine and the tools; you write the instructions, connect the calendar and CRM, buy the phone number and test every path |
| Priced by | Calls or minutes a month on a plan: Upfirst from $24.95 for 30 calls, Dialzara from $29 for 60 minutes, Rosie $149 for 1,000 minutes; Outcraft from $300 for 100 leads | Usage: Vapi $0.05 a minute plus the model, voice and line; Retell $0.07 to $0.31; Bland $0.12 to $0.14; ElevenLabs plans from $1 |
| Time to live | The same day; Upfirst reviewers report going live in under 20 minutes | Days to weeks, and someone has to keep tuning it |
| Fits | A business that wants the phone answered or the leads called | Agencies, developers, call centers, and businesses with a job no service covers |
Agencies sit in between: they build on a platform and sell the result as a service, often inside HighLevel. If an agency quotes you a monthly fee, ask which platform it runs on and what the per-minute cost underneath is.
Ready-made AI voice agents, by job
These are the tools our guides rank first for each job, with the entry price from each vendor's pricing page. The guides have the full comparisons, the test plans and the complaints.
Answering calls
- Upfirst, our overall pick: per-call billing from $24.95 a month for 30 calls, with booking, transfers, texting and recordings on every plan, and spam calls not counted. G2 4.9 from 26 reviews (G2).
- Dialzara for short calls on a budget: from $29 a month for 60 minutes, booking included.
- Rosie for 250 to 500 calls a month: $149 for 1,000 minutes with booking and live transfers.
- Smith.ai when you want a person behind the AI: North America-based receptionists take over when the AI can't help, from $150 a month for 75 calls.
Twelve services are priced at the same call volumes on our home page, with a calculator for yours.
Store support and shopper calls
- Ringly.io answers a Shopify store's support line around the clock: order status, returns, exchanges, stock.
- Ava AI puts AI on both jobs: the support line from $29 a month, and calls to shoppers who abandon checkout on the $99 plan.
- Callsy is the cheapest test of cart calls: 20 free calls, then $29 a month for 50.
Calling leads and customers
- Outcraft AI is a done-for-you sales agent: it calls, texts, emails and messages new leads on WhatsApp within seconds, books the meeting, and also calls abandoned checkouts, failed payments and cancellations. $300 a month for up to 100 leads, monthly, no setup fee (Outcraft).
- 11x Julian does the inbound call for mid-market and enterprise sales teams, by quote.
Platforms to build your own AI voice agent
If no service fits, or you are an agency, you build. The platforms below give you the engine, a web editor for the instructions, phone numbers and the connections to calendars and CRMs. Prices checked 9 October 2026.
| Platform | Published price | To start | Good to know |
|---|---|---|---|
| Vapi | $0.05 a minute, plus the transcriber, model, voice and line, billed at the providers' cost | $5 in credits; 1 number; 4 calls at once | Its own calculator puts 1,000 minutes at $82 to $129. Core plan $29 a month for 5 numbers and 10 calls at once; HIPAA costs $2,000 a month (Vapi) |
| Retell AI | $0.07 to $0.31 a minute, by the voice and model you pick; its example comes to $0.11 | $10 in credits; 20 calls at once free | Numbers $2 a month; calls $0.015 a minute; add-ons such as a knowledge base or denoising at $0.005 a minute each. G2 4.8 from 2,638 reviews on 1 October 2026 (Retell, G2) |
| Bland AI | $0.14 a minute on Start; $0.12 on Build with a $299 monthly fee | No fee, no card; an inbound number included | One rate covers the model, transcription and voice; the line is extra, at the price Twilio charges. Start allows 100 calls a day and 10 at once; Build 2,000 a day and 50 at once (Bland) |
| ElevenLabs Agents | Plans from $1 a month for 75 minutes to $990 for 12,375; about $0.08 a minute at the plan rates | Free plan: 15 minutes, 4 calls at once | The language model and the phone line are billed on top; Pro is $99 for 1,238 minutes and 20 calls at once (ElevenLabs) |
| Synthflow | Enterprise contracts from $30,000 a year | Sales-led | Scoped by call volume, concurrency and integrations; no per-minute price published (Synthflow) |
For phone lines bought separately, Twilio charges $0.014 a minute for US outbound calls and $0.0085 for incoming calls to a local number (Twilio), checked 1 October 2026.
What the platform price leaves out: the hours to write and test the instructions, a phone number and its carrier, the calendar and CRM connections (Zapier or code), call monitoring, and someone to fix the agent when a caller finds a path you didn't test. For a business with one phone line, that work is what the higher monthly price of a ready-made service pays for.
What a minute of AI voice costs
Take a business with 150 two-minute calls a month, 300 minutes.
| Option | 300 minutes a month | What is included |
|---|---|---|
| Ready-made answering service | $59 to $270 | Twelve services priced on our home page; booking, transfers and support included (checked 30 September 2026) |
| Bland AI, Start | about $42 + line | $0.14 a minute; add Twilio at $0.0085 a minute inbound |
| Retell AI | about $40 | Its $0.11 example, plus $2 for the number and $0.015 a minute for calls |
| Vapi | $25 to $39 + line | Its calculator's $82 to $129 per 1,000 minutes, scaled |
| ElevenLabs Agents, Creator | $11 + model + line | 275 minutes included on the $11 plan; the rest at the plan rate |
Platform figures from the pricing pages checked 9 October 2026; the ready-made range from the vendors' pages checked 30 September 2026. Platform totals leave out your build and maintenance time.
Per minute, the platforms win. Per month, once you count the build, the ready-made service usually wins below a few hundred calls, and the platform wins at call-center volumes or when you need a job nobody sells ready-made. Outbound sales calls are priced differently again, per lead rather than per minute: Outcraft charges $3 a lead at 100 leads a month and $2 at 1,000, with the texts, emails and WhatsApp messages for each lead included (Outcraft). Our free case study works the numbers for your own volume.
What separates a good AI voice agent from a bad one
- It answers fast and lets people interrupt. The complaints in Upfirst's reviews, the best-rated service we cover, are pauses, talking over callers who pause, and trouble with background noise (G2, Capterra). Those are the three things to listen for in a trial.
- It says what it is and offers a person. In a Gartner survey of 5,728 customers (December 2023), 64% said they would prefer companies didn't use AI for customer service, and the top worry was reaching a person (Gartner). An agent that says it's an AI, keeps the call short and transfers on request loses fewer callers than one that pretends.
- It does one job to the end. Booking means the appointment lands in your calendar with the caller's details; taking a message means the message reaches the right person; transferring means the call connects. Half-done is worse than a voicemail.
- It knows what it doesn't know. Prices, availability and policies should come from your data, not the model's guess; a good agent says “I'll have someone call you back” instead of inventing an answer.
- It logs everything. Recordings, transcripts and a summary after each call are how you find out what the agent said.
Rules for AI voice agents
A summary, not legal advice.
- Answering calls needs no consent from the caller, but recording does in some US states. Have the agent say the call may be recorded.
- Calling out to sell needs written consent. In February 2024 the FCC ruled that the TCPA's rules on artificial voices cover AI-generated voices (FCC 24-17), and those rules require prior express written consent for telemarketing calls made with one (47 CFR 64.1200). The wording goes on the form that collects the number; our speed-to-lead guide has an example to show your lawyer.
- Disclosure may become law. The FCC has proposed requiring callers to say at the start of a call that it uses AI-generated technology (Federal Register). Most vendors' terms already make you responsible for it.
- Europe. Article 13 of the ePrivacy Directive requires prior consent before direct marketing calls by automated calling machines (EUR-Lex).
- Calls from AI to you are a different matter: Google says its agent's calls to businesses are monitored and recorded and are made in every US state except Indiana, Louisiana, Minnesota, Montana and Nebraska (Google). See when the caller is an AI.
How to test an AI voice agent
- Call it from a mobile in a noisy place and from a quiet landline. Note every pause longer than a breath.
- Interrupt it mid-sentence. It should stop and listen.
- Ask for a price it was given and one it wasn't. The second answer should be “I'll check” or a transfer, never a number.
- Book an appointment, then check the calendar entry: name, number, time, reason.
- Ask for a person. Time the transfer, and check what happens when nobody picks up.
- Speak Spanish, or whatever your second language is, and see whether it follows.
- Say “stop calling me” on an outbound test and check that the number is marked do-not-call.
- Read the transcript and listen to the recording. Then do all of it again a week later, after the vendor's next update.
Questions people ask
What is an AI voice agent?
Software that answers or makes phone calls and holds the conversation itself: it understands what the caller says, works out a reply with a language model and your instructions, speaks it in a natural voice, and can act during the call, such as booking an appointment or transferring to a person. AI receptionists and AI sales agents are AI voice agents built for one job.
How does an AI voice agent work?
In a loop: speech-to-text turns the caller's words into text, a language model decides what to say and whether to use a tool (calendar, CRM, transfer), and text-to-speech turns the reply into a voice. Some engines combine the listening and speaking steps. The call runs over a normal phone line from a carrier such as Twilio.
What is the difference between an AI voice agent and an IVR?
An IVR is a menu: “press 1 for sales, 2 for support”. It follows a fixed tree and cannot answer a question it wasn't built for. An AI voice agent talks, listens, can be interrupted and handles questions in any order. Most AI agents can still transfer to your existing phone system or menu.
How much does an AI voice agent cost?
Ready-made: from $24.95 a month for 30 calls (Upfirst) or $29 for 60 minutes (Dialzara), up to about $270 a month for 150 two-minute calls at the dearer services. Platforms: $0.05 a minute plus the model, voice and line on Vapi, $0.07 to $0.31 on Retell, $0.12 to $0.14 on Bland, and about $0.08 plus the model and line on ElevenLabs. Prices checked 9 October 2026.
Can I build my own AI voice agent?
Yes, on Vapi, Retell, Bland or ElevenLabs, without code for the basic version: you write the instructions in a web editor, pick a voice, buy a number and connect the calendar through Zapier or an integration. Expect days of testing before it handles real callers well, and plan for someone to keep tuning it.
What is the best AI voice agent for a small business?
For answering the phone, Upfirst: per-call billing from $24.95 a month with booking and transfers on every plan, and a 14-day trial without a card. For calling new leads, Outcraft: $300 a month for up to 100 leads, monthly. Our guides compare twelve answering services and the lead and cart callers in detail.
Do callers know they are talking to an AI?
Often, and the ones who don't may feel misled when they find out. Have the agent say it's an AI at the start, and make it easy to reach a person. The FCC has proposed making an AI disclosure mandatory at the start of calls that use AI-generated technology.
Is it legal to use an AI voice agent?
Yes. Answering calls needs no consent, though call recording is regulated in some US states. Sales calls made with an AI voice need the person's prior express written consent under the FCC's TCPA rules, and automated marketing calls in the EU need prior consent under the ePrivacy Directive.
Can an AI voice agent book appointments?
Yes, when it's connected to your calendar: Upfirst books into Google, Outlook, Calendly, Acuity, Square and Clio; Dialzara and Rosie book with live availability; Outcraft books sales meetings into the right rep's calendar. On a platform, you connect the calendar yourself.
Can an AI voice agent make outbound calls?
Yes. Outcraft, 11x's Julian and Verse call new leads; Outcraft, Callsy, Ava AI, Conversa and Callfy call shoppers who abandon checkout; Outcraft also calls failed payments and cancellations. Each outbound sales call to a US number needs the person's written consent to calls with an AI voice.
What is the difference between an AI voice agent and an AI receptionist?
An AI receptionist is an AI voice agent built for one job, answering a business's phone: greeting, booking, messages and transfers. “AI voice agent” is the wider term and also covers agents that make calls and agents you build yourself on a platform.
Why is an AI calling my business?
Probably an assistant calling on a customer's behalf. Google's agent phones businesses to check prices and availability and to book, in every US state except Indiana, Louisiana, Minnesota, Montana and Nebraska, and Google says the calls are monitored and recorded. Meta and several start-ups do the same. Our home page explains what to do when the caller is an AI.
Sources
- Vapi, Retell AI, Bland AI, ElevenLabs (Agents) and Synthflow pricing pages, checked 9 October 2026; Twilio US voice pricing, checked 1 October 2026; G2 reviews for Retell AI (1 October 2026) and Upfirst; Capterra reviews for Upfirst
- Upfirst, Dialzara, Rosie, Smith.ai, Ringly.io, Ava AI, Callsy, 11x and Outcraft AI pricing and product pages (vendor-published); see each guide for its own check date
- FCC 24-17 (8 February 2024); 47 CFR 64.1200; FCC proposed rule (Federal Register, 10 September 2024); Directive 2002/58/EC, Article 13 (EUR-Lex)
- Gartner press release, 9 July 2024; Google Business Profile Help on calls made by Google's AI