AI Receptionist for Small Business: Buy or Build One (2026)

An AI receptionist is a voice agent that answers your business phone, handles common questions, books appointments and passes the call to a person when it should. For most small businesses it works best as the front desk for routine calls, after-hours calls and overflow, not as a full replacement for people. You can buy a ready-made service, some of which start free for a handful of calls, or build your own on a voice platform that bills by the minute.

What an AI receptionist can and cannot do

Knowing the limits up front saves you from angry callers in week one.

The "Partial" rows are why a good setup repeats important details back to the caller and transfers anyone upset. The "No" rows are rules you write into the prompt, not risks you hope never happen.

Buy or build?

There are three ways to get one, and the right choice depends on your call volume and how much control you want.

Two ready-made examples with public prices:

• Smith.ai AI Receptionist: a free plan with 25 calls a month, Pro from $150 a month and Enterprise from $500 a month. It books appointments, qualifies leads and can transfer callers to a live North America-based receptionist (Smith.ai pricing).
• Goodcall: Starter at $79, Growth at $129 and Scale at $299 a month, priced by unique callers. You can build and test a demo agent free and pay once you connect a phone number (Goodcall pricing).

For building, the main platforms are Retell AI, ElevenLabs Agents and Vapi; we compare their pricing in the best AI agent platforms. The walkthrough below uses Retell, because it has a receptionist template, free browser testing, calendar integrations and a call transfer tool.

How a good receptionist call flows

Design the call before you open any tool. This is the shape that works for most businesses:

How to build an AI receptionist with Retell

1. Write the call sheet

On one page, list the 10 most common reasons people call, the answer to each, what details to collect and when to transfer. This sheet becomes your knowledge base and your prompt, and it is the step that decides quality.

2. Create the agent from the template

1. Sign up. New Retell accounts start with $10 of free credit and need no payment method (Retell quick start).
2. Create an agent. In Agents, click Create an agent and choose Single prompt.
3. Start from the Receptionist template. You can also describe your use case in plain English and let Retell draft the agent for you.

3. Write the prompt

Replace the template's prompt with your own. This version covers identity, disclosure, tasks, limits and handoff:

You are the virtual receptionist for [BUSINESS NAME], a [TYPE OF BUSINESS] in [CITY]. Open every call with: "Thanks for calling [BUSINESS NAME]. I'm the virtual assistant, an AI, and this call is recorded so we can help you. How can I help today?"
Your jobs: answer questions using only the knowledge base, book or change appointments with the calendar tools, and take messages.
Keep answers short and natural, one or two sentences. Repeat names, phone numbers, dates and times back to the caller to confirm them.
Never quote a price, policy or availability that is not in the knowledge base or the calendar. If you do not know, say so and offer to take a message.
Transfer the call to [HUMAN PHONE NUMBER] when the caller asks for a person, is upset, has a complaint or billing problem, or needs something you cannot do.
If someone describes an emergency, tell them to hang up and call [EMERGENCY NUMBER] right away.
Never take card numbers or passwords. If payment is needed, offer to text a secure payment link.
Before ending, summarize what happens next.

4. Add your knowledge base

Attach your call sheet, price list and FAQ page as documents, text or website URLs in the agent's knowledge base settings. Keep each fact in one place, so an updated price never contradicts an old one.

5. Connect your calendar

Connect your calendar on Retell's Integrations page, then add Check Availability and Book Appointment to the agent's functions and enter the ID of the event type it should book (Cal.com tools). Calendly works the same way.

6. Add the human handoff

Add the Transfer Call function with your number in international format (for example +1 followed by the number). Choose a cold transfer to hand the call straight over, or a warm transfer, where the AI stays on the line and can brief you privately before connecting the caller (transfer call docs).

7. Test it in your browser

Click Test to talk to the agent through your microphone. Browser test calls are free, but transfers only work on real phone calls, so test the handoff after step 8.

8. Get a phone number

In Phone Numbers, click Buy New Number and assign your agent to it. Retell-managed numbers cost $2 a month, or $5 for toll-free, and are available in the US and Canada; elsewhere, connect your own phone provider. Many owners keep their existing number and set their phone carrier to forward unanswered or after-hours calls to the agent's number.

9. Set privacy and retention

By default, Retell stores call recordings and transcripts. Under the agent's Data Storage Settings you can keep everything, keep everything except personal details, or store only basic call data, and you can set a retention period so old calls delete themselves (data storage settings).

10. Go live in stages

1. After hours first. Forward only calls outside opening hours for the first week or two.
2. Then overflow. Add calls you cannot answer during busy times.
3. Then all calls. Switch over fully once a week of transcripts looks right.

Keep reading a sample of transcripts every week and fix the prompt or knowledge base wherever the agent stumbled.

What it costs

Building is usually cheapest per call. Retell charges $0.07 to $0.31 per minute depending on the voice and AI model you pick (Retell pricing):

A worked example: 300 calls a month at three minutes each is 900 minutes. On Retell that is $63 to $279 for the minutes plus $2 for the number. Compare that with Smith.ai's Pro plan, which starts at $150 a month for 75 calls, or Goodcall, which prices by the number of unique callers.

Rules for recording, disclosure and privacy

This is general information, not legal advice. Rules depend on where you and your callers are, so check with a local lawyer if you are unsure.

Platforms differ on that last point. Retell offers a BAA you can sign yourself at no extra fee (Retell compliance), Vapi sells HIPAA compliance as a $2,000-a-month add-on (Vapi pricing), and ElevenLabs lists BAAs on its Enterprise plan (ElevenLabs pricing).

Handing off to humans

The handoff is where trust is won or lost. Write these rules into the prompt and test each one:

Retell's warm transfer can stay on the line, whisper a summary to you that the caller does not hear, and then connect you. Make sure the number it transfers to is one that someone actually answers.

Before you switch it on for real customers, tick these off:

The same design works for a website chat assistant. Our n8n AI agent tutorial builds one that answers from your price list and saves leads. For more front-desk ideas by industry, see these AI agent examples.

What to do next

Write your call sheet this week: the 10 most common reasons people call, the answers and your transfer rules. Then build a test agent on Retell's free credit and call it yourself until it handles all 10 smoothly, before you route a single real call to it. AI receptionists are one part of answering every lead automatically; our guide to AI automation for small business shows where they fit, and the Autopilot course on lead automation is in early access.