An AI Business Assistant That Answers Every Call and Books the Work

5.0

ON G2

General AI business assistants handle your inbox, calendar, and documents, and leave the phone ringing. Retell AI is the AI business assistant for that phone line: a voice agent that answers every inbound call, books appointments straight into your calendar, captures and qualifies leads, answers routine questions from your own content, and follows up by phone. It works on your existing number, 24/7, in 31+ languages, so a missed call never turns into a lost customer.

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Trusted by over 3,000 businesses powering 30+ million calls per month.

How It Works

Go from build to a live call in a day, on your existing number.

Build the agent

Point the agent at your website, services, hours, and pricing through a knowledge base that syncs as that content changes, so it answers callers the way you would. Define the call flow with a drag-and-drop builder: greeting in your business name, intent detection, availability check, booking, message-taking, and transfer rules, then connect your calendar and CRM. No engineering team is required for a standard agent.

Test against front-desk scenarios

Run the agent through simulation against common front-desk scenarios before it touches a customer: a new booking, a reschedule, an hours-or-pricing question, an after-hours call, and a frustrated caller. Each run scores accuracy and shows where the agent guesses instead of looking up, so you fix the flow, rerun, and validate at volume rather than finding gaps in production.

Connect your line and go live

Connect your line through SIP trunking and forward calls to the agent, all of them, only the ones you miss, or only after hours, and set the conditions for human escalation. Go live on one line, confirm the booking and transfer rates, then expand. Your existing carrier and phone number stay in place.

Monitor and retrain

Every call is transcribed, summarized, and tagged by outcome, and every booking lands in your calendar and CRM. Watch booking rate, missed-call recovery, and transfer rate in a dashboard, catch the questions the agent fumbles, and retrain the flow, with quality review across 100% of calls rather than a small sample.

Use Cases

Answer every call and greet in your name

The agent picks up on the first ring and greets callers in your business name, so the line never goes to voicemail or a busy signal, even when many people call at once. It answers hours, location, pricing, and service questions from the connected knowledge base, covers nights, weekends, and holidays, and handles callers in 31+ languages with automatic language detection.

Book appointments straight into your calendar

The agent checks live availability and books appointments on Cal.com or Google Calendar, then reschedules and confirms during the same call. It sends confirmations and reminders so fewer customers no-show, acting as the front desk for clinics, salons, law firms, and home services without hiring a part-time receptionist.

Capture and qualify every lead

The agent identifies why the caller is phoning, gathers the details you need, and qualifies the lead in natural conversation, then routes hot leads to the right person with a warm call transfer that attaches the full transcript. It responds the moment a lead comes in, since speed-to-lead is the strongest predictor of whether it converts.

Follow up and remind by phone

The agent places appointment reminders, confirmations, review requests, and re-engagement calls through batch call campaigns, and takes a message when the right person is out, logging it to your CRM with the transcript attached.

Cover overflow and after-hours

The agent fields overflow and after-hours calls through an AI answering service, so your team only handles what needs them and no call rolls to voicemail.

Serve callers in 31+ languages

Native-quality speech across 31+ languages with automatic language detection, so one agent serves callers in the language they start in.

Compliance

Regulated businesses route real calls through the agent, so the security baseline comes standard.

SOC 2 Type II

Call data runs on SOC 2 Type II certified infrastructure, meeting enterprise security requirements.

HIPAA

Healthcare practices and other regulated teams deploy under HIPAA with a self-service BAA portal available from the dashboard.

GDPR

Caller data is processed under GDPR, covering consent and access rights for callers in the EU.

PII Redaction

Sensitive details are masked in transcripts automatically, alongside single sign-on and role-based access.

Feature

Why businesses choose Retell AI for their phone line

Build

Deploy

Monitor

Sounds like your business

Pick from 100+ lifelike voices or clone your own, and tune tone and language so the agent matches a dental office or a law firm and greets callers in your name.

Books into your calendar, not just a message pad

The agent checks live availability and writes the appointment into Cal.com or Google Calendar during the call, so a captured call becomes a booked job. Pine Park Health raised scheduling NPS by 38% after putting calls through a voice agent. Results vary by setup.

Answers in roughly 600 milliseconds

End-to-end latency of about 600ms with proprietary turn-taking means callers do not sit through dead air or talk over the agent. Interruptions and barge-in are handled the way a strong receptionist handles them.

Never a missed call, never a busy signal

The agent answers every call at once, around the clock. That matters because callers who reach voicemail rarely leave one and rarely call back, and industry research puts the average missed call at about $12.15 in lost value. Results vary.

Scores 100% of calls

Every call is transcribed, summarized, and tagged by outcome through post call analysis, and every booking lands in your calendar and CRM. Watch booking rate, missed-call recovery, and transfer rate in a dashboard, catch the questions the agent fumbles, and retrain the flow, instead of reviewing a small sample by hand.

Integrations

Seamless 
Integrations with Your
Tech Stack

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Hubspot
Twillio
Vonage
Go High Level
8n8
Zapier
Salesforce

Hubspot
Twillio
Vonage
Go High Level
8n8
Zapier
Salesforce

Avaya
Genesys
Five9
Amazon Connect
Telnyx
Make
Cal.com

Avaya
Genesys
Five9
Amazon Connect
Telnyx
Make
Cal.com

Pricing

Cut Costs by 90% with AI phone Agents

Pay as you go

$0 to start.

$0.07–$0.12 per minute – Pay only for what you use.

60 mins of free access.

20 concurrent calls.

10 Free Knowledge Bases.

Get Started

Enterprise Plan

For companies with large volumes, data or deployment requirements, or support needs.

White glove service for your use case.

Premium support with dedicated solution engineer teams.

Custom pricing and concurrent calls based on your needs

Talk To Sales

FAQ

Frequently asked questions.

What is an AI business assistant?

The term covers two different things. One is a productivity assistant that handles admin work like email, scheduling, research, and documents. The other is a phone assistant that answers your business calls, books appointments, and captures leads in live conversation. Retell is the second kind: a voice agent that picks up the phone, holds a multi-turn conversation, acts during the call, and transfers to a person when needed. It differs from a basic chatbot or touch-tone IVR because it understands intent and takes action rather than reading a menu.

Will it replace my receptionist or staff?

Usually it augments them. Many businesses route first contact, overflow, and after-hours calls to the agent and keep staff for in-person work and complex cases. It transfers anything it should not handle to a person with the full context attached.

Can it book appointments into my calendar?

Yes. It checks live availability and books, reschedules, and confirms on Cal.com or Google Calendar during the call, then sends a confirmation. No message pad, no callback tag.

Is an AI business assistant the same as a virtual receptionist?

For phone work, yes, and that is the honest distinction worth drawing. A virtual assistant handles admin and executive tasks like email and research and usually does not cover the phone live. If your problem is missed calls, you want a receptionist, and Retell plays that role: it answers, books, and routes calls in live conversation.

Can it manage my email and calendar like other AI assistants?

It is voice-first. It answers your phone calls and writes appointments into your calendar, but it does not manage your inbox, write documents, or take meeting notes. Pair it with a productivity assistant for that, and let Retell own the phone channel those tools ignore.

How much does it cost?

Pay-as-you-go at $0.07 per minute with no platform fee or contract, plus $10 in free credit to start. You pay for minutes worked, not seats, which is why a busy line still costs less than a part-time front desk.