For a small business, an AI phone answering service typically costs between $25 and $300 a month. That's a monthly fee plus either a per-minute rate of roughly $0.35–$0.50 once the included minutes run out, or $1–$3 per call. A human answering service handling the same calls usually costs several times as much. Threll's smallest plan is €59 a month plus €0.35 a minute, so 300 minutes a month comes to €164. The plan you choose matters less than how many minutes the agent actually talks.
What the market charges
Most AI receptionist products for small businesses publish their prices. The entry plans look cheap, but what they include varies widely. Prices were checked on October 29, 2026.
| Provider | Entry plan | Included | After that |
|---|---|---|---|
| Upfirst | $24.95/mo | 30 calls | $1.50/call |
| Dialzara | $29/mo | 60 min | $0.48/min |
| Goodcall | $79/mo | 100 unique callers | $0.79 per caller |
| Smith.ai AI Receptionist | $0/mo (Free) | 25 calls | $3.00/call |
| Threll | €59/mo | none | €0.35/min |
So the monthly fee on its own tells you little. At 120 calls a month, Upfirst's $24.95 Starter plan comes to $159.95, more than Dialzara's $99 Business Pro plan at $135 for the same calls (300 minutes). Price every option at the same volume before comparing.
Four ways vendors charge
- Per minute. You pay for talk time. It's easy to check against your call log, but the bill follows your volume.
- Per call or per caller. Common for answering services. A 30-second call costs the same as a ten-minute one.
- A bundle of included minutes. Predictable as long as you stay inside it. Anything over is billed per minute.
- Per seat. Common for business phone systems, rare for AI agents.
Which unit works in your favor depends on who carries the risk when volume changes. We cover that in choosing the pricing unit for a voice agent.
If you'd rather build your own, developer platforms charge per minute and leave the parts to you. Vapi charges $0.05 a minute for hosting, with speech and language models passed through at cost. Retell AI quotes $0.07–$0.31 a minute for its voice agents. A Twilio US local number is $1.15 a month plus $0.0085 a minute for inbound calls. Then you pay for the engineering time it takes to make it work.
What drives the bill
Minutes. Calls per month times average length. The most important choice is which calls the agent takes. If it only answers when nobody else can, and after hours, the volume is a fraction of your full call log.
Telephony and numbers. Most businesses keep their number and forward calls to the agent when nobody picks up or after hours. Check whether the vendor charges for the number separately, and what your carrier charges for forwarding. If you bring your own SIP trunk or Twilio account, some vendors lower the per-minute rate because you pay for the phone traffic yourself. At Threll it's €0.10 a minute less.
Setup. €0 if you set it up yourself. Threll quotes €450–1,300 for setup help and from €1,300 for complex integrations.
Integrations and features. Calendar booking, lookups in your business systems and outbound calls often sit in higher tiers. At Threll, Start is inbound only with no integrations, Pluss allows two and Premium ten.
Simultaneous calls. If three people call at once, you need three free lines. Threll Start has two inbound lines, and an extra line is €4.50 a month. More on where that ceiling sits.
Commitment. Annual billing is usually cheaper in exchange for a commitment. At Threll, paying yearly gives 20 percent off for a twelve-month term, which brings Start to €47 a month. Monthly billing has no commitment.
