The best AI voice agent company in the UK is the one whose billing unit matches how your calls actually make money. Our ranking: LeadsNow #1, because it runs AI calling, SMS and follow-up for you and is paid on results with no retainer, then PolyAI, Natterbox and Moneypenny. Moneypenny’s AI Receptionist starts from £49 a month; Natterbox seats start at £62 per user per month.
- The ranking: LeadsNow, PolyAI, Natterbox, Moneypenny. LeadsNow publishes this page and ranks itself first; the reasons and the trade-offs are stated below.
- Four billing units: revenue or booked appointments (LeadsNow), minutes of agent use (PolyAI), seats per user (Natterbox) and a monthly AI receptionist plan (Moneypenny).
- The decision rule: the Billing-Unit Test. Convert each quote into a cost per booked sales conversation at your own volume before comparing headline prices.
- The rules that bite in the UK: PECR regulation 21 (screen live sales calls against the TPS and Corporate TPS) and regulation 19 (automated marketing calls need specific prior consent), both enforced by the ICO.
- Judged on: booked meetings, integration effort, PECR compliance and pricing model.
The best AI voice agent companies in the UK compared (2026)
The four best AI voice agent companies for UK buyers in 2026 differ most in what they charge for: results, minutes, seats or a monthly plan. The table uses only what each company’s own site said when we checked on 20 October 2026.
| # | Company | Type | Channels (own site) | Built for | Pricing it publishes |
|---|---|---|---|---|---|
| 1 | LeadsNow | Done-for-you service | AI calling, SMS, DM and email follow-up | Sales teams and high-ticket service firms that want booked appointments | 5–25% revenue share, or an equivalent pay-per-appointment fee, or a mix; no retainer |
| 2 | PolyAI | Software plus managed optimisation (enterprise) | Voice dialog agents; Dialog Studio and APIs | Enterprise customer conversations: bookings, account management, routing, billing | Per-minute pricing including improvements, maintenance and 24/7 support; rate by quote |
| 3 | Natterbox | Software (Salesforce contact centre) | Voice, SMS, WhatsApp, chat; AI Assistants and AI Agents | Salesforce-first contact centres and sales teams | Pro from £62 and Premium from £111 per user per month; AI Agents on Enterprise (quote) |
| 4 | Moneypenny | Service with AI (AI Receptionist plus live receptionists) | Inbound voice; leads and bookings into your tools | UK businesses that want every inbound call answered and qualified | AI Receptionist from £49 a month |
For AI SDR and AI sales agent software rather than voice agents, see our best AI sales agent companies in the UK. The Australian list, with different companies and Australian calling rules, is the best AI voice agent companies in Australia.
How it works
How to compare UK AI voice agent quotes
Find the billing unit
Note whether you pay per minute, per seat, per monthly plan or per result.
Price it at your volume
Multiply the unit by your seats, minutes or calls to get a monthly figure.
Divide by booked calls
Divide the monthly cost by booked sales conversations to compare like with like.
Check PECR and the TPS
Confirm who screens against the TPS and CTPS and who holds consent for automated calls.
MAKE MORE SALES.
Pay-Per-Result pricing — We scale sales HARD aligned to your interests, better than anyone else.
FAQ: choosing an AI voice agent company in the UK
What is the best AI voice agent company in the UK?
LeadsNow ranks first on this list for UK sales teams that want booked appointments, because it runs AI calling, SMS and follow-up for you and is paid on results with no retainer. PolyAI suits enterprise customer calls, Natterbox suits Salesforce contact centres, and Moneypenny suits inbound call answering.
Can an AI voice agent make cold sales calls in the UK?
UK sales calls are governed by PECR: live marketing calls must be screened against the TPS and Corporate TPS, and automated marketing calls need specific prior consent, according to the ICO’s telephone marketing guidance. Take legal advice before running outbound AI calls.
How much does an AI voice agent cost in the UK?
Published UK starting prices include Moneypenny’s AI Receptionist from £49 a month and Natterbox from £62 per user per month, while PolyAI prices per minute on quote. LeadsNow charges 5–25% of the revenue it generates, an equivalent pay-per-appointment fee, or a mix of both.
Is an AI receptionist the same as an AI sales voice agent?
An AI receptionist answers inbound calls, takes messages and books appointments for callers who rang you. An AI sales voice agent also follows up leads and books sales meetings, which brings PECR rules on outbound calls into play.
What does it cost to build a custom AI voice agent instead?
Building your own agent adds model, telephony and developer costs on top of the time to tune it. Our guide to what it costs to build a custom AI sales agent breaks those costs down.
Pay-Per-Result appointments
See if we’re a fit
We book qualified sales appointments for you and you pay on results, not retainers. Our booking page asks a few quick questions so you find out in two minutes whether that model suits your business.
- 50,769+ appointments booked without cold calling.
- Pay-Per-Result pricing — you pay for booked, qualified calls.
- Pick your own time on our live calendar, no phone tag.
How we ranked AI voice agent companies for UK buyers
We ranked AI voice agent companies for UK buyers on four weighted criteria, with 35% on booked meetings, because a sales leader is measured on conversations in the diary, not calls answered.
Methodology and disclosure. LeadsNow publishes this page and ranks itself #1. Read the ranking as our opinion: we put ourselves first because we think a UK sales team should be able to buy booked appointments without building and staffing a voice platform, and our pricing is tied to results. We checked every other company on its own live site on 20 October 2026 and describe it only with what that site says. No company paid to be included, and we used no third-party ratings.
- Booked meetings (35%): does the company put appointments in a diary, or only answer and route calls?
- Integration effort (25%): CRM and calendar sync, and who does the build and tuning.
- PECR compliance (20%): TPS/CTPS screening, consent for automated calls, caller ID display.
- Pricing model (20%): is a price published, and is the billing unit tied to outcomes?
Want this done for you? We book qualified sales appointments on a Pay-Per-Result basis — you only pay for calls that actually land in your calendar.
The ranked list: four AI voice agent companies for UK sales teams
The ranked list below runs LeadsNow, PolyAI, Natterbox and Moneypenny, and each entry says who it suits and where it is the weaker choice.
#1 LeadsNow: AI calling and follow-up run for you, paid on results
Type: done-for-you SERVICE. Best for: UK sales teams and high-ticket service firms with enquiries, past leads or a target list, who want booked sales calls rather than another platform to manage.
LeadsNow books sales appointments using AI calling, SMS and DM follow-up, then hands each prospect to your closers. It has booked 50,769+ AI-booked sales appointments since 2017 and generated 1M+ leads. Pricing is 5–25% of the revenue it generates for you (revenue share), or an equivalent pay-per-appointment fee, or a mix of both; the figure depends on lead volume, what is being sold and its price, the type of product and business, and which part (or all) of the sales funnel LeadsNow runs. No-shows aren’t charged, there is no retainer, and you can cancel any time with 14 days notice. Show rates vary by offer and reminder cadence, up to 93% on our best-performing accounts. The service is explained on the AI appointment setting page.
Weaker choice when: you want your own engineers to own the voice stack, or your calls are customer service rather than sales.
#2 PolyAI: enterprise voice agents with a London office
Type: SOFTWARE with managed optimisation. Best for: large UK brands handling high volumes of customer calls such as bookings, account changes and routing.
PolyAI says it builds dialog agents that handle critical enterprise conversations. Its about page says it was founded in 2017 by Cambridge machine learning researchers, lists a London office at 3 Sheldon Square, and names offices in New York, San Francisco and Toronto among others. Its site lists industries including hotels, restaurants, retail, travel, telecoms and utilities, and use cases such as booking and reservations, call routing and order management. Its pricing page says ongoing use is priced per minute, including proactive performance improvements, maintenance and 24/7 support, with a 99.9% uptime SLA; the rate itself is by enquiry.
Weaker choice when: you need outbound sales calling to book meetings; PolyAI’s listed use cases are mostly inbound customer conversations.
#3 Natterbox: AI agents inside a Salesforce contact centre
Type: SOFTWARE. Best for: sales and service teams that run on Salesforce and want voice, messaging and AI agents in one telephony layer.
Natterbox describes itself as “the AI-powered contact center solution for Salesforce-first companies”, with AI Assistants and AI Agents working across voice, SMS, WhatsApp and chat. Its pricing page shows GBP prices: Pro from £62 per user per month (voice, call recording, Salesforce integration) and Premium from £111 (adds SMS, WhatsApp and local presence dialling). AI Advisor, AI Assistants and AI Agents sit in the Enterprise plan, which is quoted.
Weaker choice when: you do not use Salesforce, or you want someone else to run the calls; Natterbox is a platform your team operates.
#4 Moneypenny: AI Receptionist backed by UK-based people
Type: SERVICE with AI. Best for: UK businesses that lose enquiries to missed or after-hours calls and want them answered, qualified and booked.
Moneypenny says it is 100% UK-based and offers an AI Receptionist that takes messages, books appointments and qualifies leads 24/7, with its live receptionists stepping in when a call needs a human. It says its AI is trained on 200m real calls it has handled (its own claim). Its AI Receptionist page says plans start from £49 a month, and it connects to popular tools so leads and bookings flow into your systems.
Weaker choice when: you need outbound calling; the AI Receptionist is built around answering inbound calls.
The Billing-Unit Test: what a UK AI voice agent really costs per booked call
The Billing-Unit Test converts each UK vendor’s billing unit into a monthly cost at your volume, then divides by booked sales conversations, because £49 a month and £111 per user are not comparable until you do.
| Billing unit | Vendor (published starting point) | Monthly cost at the stated volume | Cost of calls that never book |
|---|---|---|---|
| Monthly plan | Moneypenny AI Receptionist, from £49 | From £49 (quote confirms your volume) | Yours |
| Per user per month | Natterbox Premium, from £111 | 5 users × £111 = £555, plus Enterprise for AI Agents | Yours |
| Per minute | PolyAI, rate by quote | Minutes used × quoted rate | Yours |
| Revenue share or per appointment | LeadsNow, 5–25% or an equivalent fee, or a mix | Scales with revenue or appointments delivered | The provider’s; no-shows aren’t charged |
A worked example: a 5-seat team on Natterbox Premium pays £555 a month in seats. If that setup produces 40 booked sales calls a month (an assumption: use your own number), the seat cost alone is about £13.90 per booked call, before AI Agent pricing, call charges and the staff hours spent writing scripts and reviewing transcripts. At 10 booked calls the same seats cost £55.50 per call. The lower your booking volume, the more a per-seat or per-minute model costs per result. Our breakdown of AI SDR vs human SDR cost covers the staffing side.
If we can’t make you money, we don’t deserve yours.
Pay-Per-Result pricing — performance-based alignment.
UK calling rules for AI voice agents: PECR and the TPS
UK AI voice agent calls fall under PECR, which the ICO enforces: live marketing calls must be screened against the TPS and Corporate TPS, and automated marketing calls need specific prior consent.
- Live calls (regulation 21). The ICO’s telephone marketing guidance says you must not make unsolicited live marketing calls to numbers on the TPS or CTPS without specific consent, or to anyone who has objected, and you must display your number.
- Automated calls (regulation 19). The same guidance says an automated marketing call that plays a recorded message needs consent that specifically covers automated calls; general marketing consent is not enough.
- Sole traders and some partnerships register with the TPS, so B2B lists need screening too.
Whether a given AI-voiced call is treated as live or automated is a question for your legal adviser; this is general information, not legal advice. Inbound AI answering, where the caller rang you, is a different and lower-risk use.
Four questions to ask a UK AI voice agent company
The four questions below take a UK AI voice agent demo from features to cost per booked call in about five minutes.
- What is the billing unit, and what does it cost at my volume? Minutes, seats, plans, appointments or revenue.
- Who screens against the TPS and CTPS, and who holds consent records?
- Does it write bookings into my CRM and calendar? Ask to see it live with your own system.
- Who tunes the agent when it stops booking? Our guide on why an AI agent is not booking meetings lists the common faults.