AI receptionist vs answering service: which actually keeps the call

What an answering service actually does

An answering service is a human call centre. The caller hears "Good afternoon, [your business], how can I help?" within 4 rings. The agent has a script you provided, takes a message, and either books the appointment on a shared calendar or escalates to you. UK pricing is roughly £200-£400 a month for 60-150 calls.

Strengths: real human voice, can hold conversation with confused or anxious callers, handles edge cases off-script. Weakness: every conversation costs you a call minute, the agent does not know your business in depth, escalations to you happen 30-50% of the time which means you still get interrupted.

What an AI receptionist actually does

An AI receptionist (Vapi, Bland, Synthflow underneath the wrapper) is a voice model. The caller hears a synthesised voice within 1 ring. The AI runs a script you wrote, asks the qualifying questions you specified, checks live calendar availability, books the slot, and writes the call notes back into your dashboard. UK pricing varies: £200-£500 a month for unlimited calls in most configurations.

Strengths: 24/7 availability, never has a "bad day," handles 5 calls at once, integrates directly with your CRM or lead system. Weakness: it cannot improvise. If the caller has a non-standard request, the AI will book a callback rather than handle it live. About 8-15% of calls get the "I will have someone call you back" outcome that an answering-service human would have closed.

The numbers most operators do not check

For trade businesses running paid ads, the metric that actually matters is "what percentage of inbound calls turn into a booked job." From our :Impact client data:

Answering service: 32-45% of inbound calls become a booked job. The drag is the escalation rate plus the lag time between message-left and your callback.

AI receptionist with calendar integration: 38-52% become a booked job. The lift is from real-time booking plus 24/7 availability catching the after-hours calls that an answering service does not cover (most UK answering services are 09:00-17:00 with overnight overflow charges).

These numbers depend heavily on call complexity. Plumbing emergency at 11pm: AI wins on availability. Insurance dispute call: human wins on tone. Most retainer-trade calls are between those poles.

When AI receptionist is the wrong answer

If your average call is over 4 minutes (consultative sales, complex pricing, sensitive content), the AI handles them poorly. Wedding photographers, divorce solicitors, and addiction-recovery clinics should run a human service.

If your typical caller is elderly, the synthesised voice creates friction that costs you bookings. Mobility-aid suppliers and care-home services typically need a human.

If you trade in a regulated category that requires specific disclosures (financial advice, mortgage broking), the AI cannot guarantee compliance with the disclosure phrasing required.

When AI receptionist is the right answer

High call volume (over 30 inbound a week) with short call duration (under 3 minutes typical), where the booking is a calendar slot rather than a custom discussion. This describes most UK trades, MOT centres, body shops, beauty salons, dental clinics, physio practices.

Out-of-hours-dominant call patterns. If 30%+ of your calls land after 5pm or on weekends, an AI receptionist captures revenue an answering service would miss without a premium 24/7 contract.

Operations where you want every call note to flow into the lead pipeline without manual entry. AI receptionists tied to a CRM save the daily 30-90 minutes of call-note transcription that a human service still produces.