AI receptionist vs answering service: which suits a UK SME?
By Kieran Mullings, BEng Mechanical Engineering (UWE Bristol), technical co-founder of FlowGenix Automations Ltd.
An AI receptionist is the cheapest way for a UK SME to answer every call, at roughly 7p to 23p a minute in usage plus a one-off build. A telephone answering service costs about £208 a month for 150 calls. A full-time receptionist on the £12.71 National Living Wage costs about £28,300 a year.
FlowGenix Automations is an audit-led AI and automation consultancy for UK SMEs.
Key takeaways
- A full-time receptionist on the £12.71 National Living Wage costs a UK employer about £28,300 a year, including employer National Insurance and minimum pension.
- AI receptionist usage on a Vapi build runs at roughly 7p to 23p a minute, so 450 call minutes cost about £32 to £104.
- Mail Boxes Etc. publishes answering service pricing of £47.94 a month for 20 calls, then £1.10 to £1.50 for each extra call.
- An AI receptionist suits high-volume, repetitive calls. Complaints, regulated advice and distressed callers still need a person.
What does an AI receptionist actually do?
An AI receptionist is a voice agent that answers your business phone line, holds a natural conversation, and completes a defined job. Typical jobs are answering common questions, qualifying a new enquiry, booking an appointment into a live diary and taking a message. The agent runs every hour of the day and handles several calls at once.
A production AI receptionist combines four parts. A Twilio phone number receives the call. Vapi orchestrates the conversation, passing the caller's speech to a transcriber, a large language model and a voice such as ElevenLabs. An automation platform such as n8n then writes the outcome into your CRM or diary.
The voice AI and missed calls guide covers the revenue side, and the full list of FlowGenix services shows where voice fits.
The job list matters more than the voice quality. A receptionist scripted to "help callers" fails, because nobody defined success. The FlowGenix AI voice receptionist build starts from three to five named call types, each with its own outcome and handoff rule.
Common call types an AI receptionist handles well:
- Opening hours, location, parking and price-list questions
- New enquiries that need qualifying before a callback
- Appointment booking, rescheduling and cancellation
- Out-of-hours calls that would otherwise reach voicemail
- Message taking with an instant SMS or email summary to the owner
Key facts
- Twilio receives the inbound call and passes the audio to Vapi.
- Vapi coordinates the transcriber, the language model and the synthetic voice.
- n8n writes each call outcome into the CRM or diary.
How much does a human receptionist cost in the UK in 2026?
A full-time UK receptionist paid the National Living Wage of £12.71 an hour costs an employer about £28,300 a year. The figure covers 37.5 hours a week, employer National Insurance at 15% above £5,000 and a 3% minimum auto-enrolment pension. Holiday, sickness and lunch cover sit on top.
The National Living Wage rose to £12.71 an hour on 1 April 2026, according to GOV.UK. HMRC's rates and thresholds for 2026 to 2027 keep employer National Insurance at 15% above the £5,000 secondary threshold. Eligible small employers can offset up to £10,500 of employer National Insurance through the Employment Allowance.
The hours problem is bigger than the salary problem. A 37.5-hour week covers 22% of the 168 hours in a week. Calls that arrive at 7.30am, at lunchtime or after 5.30pm still go to voicemail. A FlowGenix audit maps every touchpoint between a call arriving and someone acting on it, then times each one, because missed calls cluster outside office hours.
| Cost line (full time, 37.5 hours) | Annual cost |
|---|---|
| Wages at £12.71 an hour (1,950 hours) | £24,785 |
| Employer National Insurance (15% above £5,000) | £2,968 |
| Minimum employer pension (3% of qualifying earnings) | £556 |
| Total employer cost | £28,309 |
| Equivalent loaded hourly cost | £14.52 |
Key facts
- The National Living Wage for workers aged 21 and over is £12.71 an hour from 1 April 2026.
- Employer National Insurance is charged at 15% on earnings above £5,000 a year.
- A 37.5-hour receptionist covers 22% of the hours in a week.
How much does a telephone answering service cost?
UK telephone answering services charge per call, per message or per minute, usually on top of a monthly base fee. Mail Boxes Etc. publishes a live answering plan at £47.94 a month for 20 calls, with extra calls charged at £1.10 to £1.50 each. A business taking 150 calls a month would pay about £208 plus VAT.
The Mail Boxes Etc. plan covers live answering from 8am to 7pm on weekdays and 9am to 3pm on Saturdays. The Mail Boxes Etc. window is 61 hours a week, or 36% of the week. Connect Communications prices by message instead of by call, starting at £14.99 a month for five messages on its Budget plan.
Answering services are good at one thing: a polite human voice that takes an accurate message. Most do not qualify the job, book it into your diary or update your CRM. Someone still has to call back. The callback gap is where FlowGenix missed-call recovery earns its keep, because the SMS and follow-up fire automatically.
Key facts
- Mail Boxes Etc. charges £47.94 a month for 20 answered calls.
- Connect Communications bills by message rather than by call.
- Most answering services take a message but do not book the job.
What does an AI receptionist cost per month?
An AI receptionist's running cost is usage-based. Vapi charges a $0.05 per minute platform fee, then passes through transcription, language model, voice and telephony costs. Published breakdowns put the all-in figure at roughly $0.10 to $0.30 a minute. At current exchange rates that is about 7p to 23p.
Take the same 150 calls a month used above, at an average of three minutes each. The total is 450 call minutes. At 7p to 23p a minute, usage costs about £32 to £104 a month. A phone number rental, any CRM seat and ongoing script management add to that figure.
The build is the larger cost, and it scales with integrations rather than call volume. Connecting a Google Calendar is quick. Connecting field service software, a dental practice management system or a multi-branch diary takes longer. FlowGenix publishes its build, retainer and usage ranges in the AI receptionist cost guide.
Book a free 30-minute audit to get your own call mix costed before you commit to anything.
The cost layers in a typical voice agent:
- Platform fee: Vapi charges $0.05 per minute for orchestration.
- Transcription: speech-to-text, billed per audio minute.
- Language model: billed per token, and usually the largest variable line.
- Voice: text-to-speech, where premium voices cost more per minute.
- Telephony: the Twilio number rental plus per-minute call charges.
Key facts
- Vapi charges a $0.05 per minute platform fee before provider costs.
- Language model tokens are the largest variable cost in most voice builds.
- Integration count drives build cost more than call volume does.
AI receptionist, answering service or human: which is cheapest?
At 150 calls a month, an AI receptionist is the cheapest option to run, at about £32 to £104 in usage. A telephone answering service costs about £208 plus VAT. A full-time human receptionist costs about £2,359 a month. Cost is only one column, so compare hours covered and what happens after the call.
The comparison below uses the published figures cited in this article. The AI column excludes the one-off build, which varies with integrations. The human column excludes recruitment, training and holiday cover.
| Factor | AI receptionist | Answering service | Human receptionist |
|---|---|---|---|
| Monthly cost at 150 calls | about £32 to £104 usage | about £208 plus VAT | about £2,359 |
| Hours covered per week | 168 | 61 (Mail Boxes Etc.) | 37.5 |
| Books into your diary | Yes, if the diary has an API | Rarely | Yes |
| Updates your CRM | Yes, via n8n | No | Manually |
| Handles complaints and distress well | No | Partly | Yes |
| Handles several calls at once | Yes | Yes | No |
The honest answer for most UK SMEs is a hybrid. The AI receptionist answers every call and handles the routine ones. Anything outside its scope transfers to a person or triggers a callback task. FlowGenix builds that handoff rule as an explicit n8n branch, so no call disappears into a gap.
Key facts
- An AI receptionist covers all 168 hours in a week.
- The Mail Boxes Etc. live plan covers 61 hours a week.
- Hybrid setups route out-of-scope calls to a named person.
When is an AI receptionist the wrong choice?
An AI receptionist is the wrong choice when call volume is low, when most calls need regulated advice, or when callers are often upset. A business taking three calls a day gains little. A mortgage adviser cannot let a voice agent give advice. A funeral director's callers need a human from the first word.
Low volume is the most common mismatch. The build cost has to be recovered from calls the business would otherwise lose. If almost every call already gets answered, the return is thin. Regulated sectors are the second mismatch. An AI receptionist can book a mortgage appointment but must not discuss products.
The third mismatch is call mix. Some businesses take mostly supplier, admin and existing-customer calls rather than new enquiries. Automating those saves time but recovers no revenue. A FlowGenix audit checks the split between new enquiries and admin calls before quoting, and sometimes the answer is a better voicemail and an SMS rather than a voice agent.
Key facts
- Low call volume rarely recovers the build cost of a voice agent.
- FCA-regulated advice must stay with a qualified human adviser.
- A FlowGenix audit checks call mix before quoting a build.
Is it legal to use an AI receptionist in the UK?
Yes. No UK law bans AI receptionists, but UK GDPR still applies to every call. You must tell callers how their data is used, keep recordings and transcripts only as long as needed, and update your privacy notice. Telling callers they are speaking to an AI assistant is good practice and costs nothing.
The Information Commissioner's Office guidance on AI and data protection sets out transparency and fairness duties for any AI system processing personal data. Call recordings and transcripts are personal data. Your privacy notice should name the purpose, the lawful basis and the retention period.
Automated decisions carry extra rules. The Data (Use and Access) Act 2025 replaced the old UK GDPR Article 22 with Articles 22A to 22D, in force from 5 February 2026. A receptionist that books appointments makes no significant decision. A system that automatically refuses someone a service might, and then safeguards apply. In a Vapi build, the opening line is a configurable field, so an AI disclosure takes one sentence to add.
Key facts
- UK GDPR treats call recordings and transcripts as personal data.
- The Data (Use and Access) Act 2025 recast the UK rules on automated decisions.
- Vapi lets the builder set the agent's opening disclosure line.
Frequently asked questions
Can an AI receptionist book appointments into my existing diary?
Yes, if the diary exposes an API. Google Calendar, Microsoft Outlook and most practice management and field service systems do. The AI receptionist checks live availability during the call and confirms the slot before hanging up. Diaries kept on paper or in a shared spreadsheet need moving to a calendar with an API first.
Will callers know they are talking to an AI?
Modern voices sound natural, so some callers will not notice. You should tell them anyway in the greeting, for example "You're speaking to our AI assistant". Transparency supports your UK GDPR duties and avoids the backlash that follows when callers find out later. Disclosure rarely reduces completed calls when the agent is genuinely helpful.
Can I keep my existing business phone number?
Yes. The usual setup forwards your advertised number to a Twilio number, so your website, Google Business Profile and printed material stay unchanged. You can also port the number to Twilio outright. Forwarding keeps the change reversible, which matters during the first weeks of testing and script tuning.
What happens when the AI receptionist cannot answer a question?
A well-built AI receptionist has an explicit fallback. The agent either transfers the call to a named person or takes a message and creates a callback task in your CRM. The fallback should trigger on topics outside scope, on repeated misunderstanding and whenever the caller asks for a human. Without that rule, edge cases silently disappear.
Does an AI receptionist work outside office hours?
Yes, and out-of-hours cover is where most of the value sits. The agent answers at 7am, 9pm and on Sundays with the same script. You decide what it does out of hours: book directly, take a message, or route genuine emergencies to an on-call mobile. The routing rule is a business decision, not a technical limit.
Sources
- GOV.UK, National Living Wage increases to £12.71 per hour
- HMRC, Rates and thresholds for employers 2026 to 2027
- Mail Boxes Etc., Telephone answering services
- Connect Communications, Call answering service costs
- Vapi, Pricing
- Information Commissioner's Office, Guidance on AI and data protection
Book a free 30-minute audit and we will map your call mix, missed-call hours and the cheapest way to cover them.
About the author
Kieran Mullings is technical co-founder of FlowGenix Automations Ltd (company number 16555743). He builds the voice agents, n8n workflows and AI search foundations behind FlowGenix client systems. He holds a BEng in Mechanical Engineering from UWE Bristol and leads the technical side of every FlowGenix audit. More at About FlowGenix.
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