Fiveleaf wrote this list, and we put ourselves first. That is our choice, not an independent ranking. Everyone else is here because they build conversational AI for customer service, they are based in the UK, and their own website says clearly what they do and who they do it for. The other eight are in no particular order, and every fact about them comes from their own site or a public source.
Last checked: 9 November 2026.
The list at a glance
| Company | Type | Best for | Based in |
|---|---|---|---|
| Fiveleaf | Builds and runs AI chatbots and voice agents | Teams that want an agent built, run and improved for them | London |
| The Bot Forge | AI consultancy and chatbot agency | Organisations that want an AI build they own | London (remote-first) |
| PolyAI | Enterprise voice AI platform | Large enterprises automating inbound phone calls | London, with offices abroad |
| EBI.AI | Conversational AI platform | UK councils and public services | UK |
| Sabio | Contact-centre consultancy | Large contact centres adding AI to their cloud platform | London |
| Worktual | AI contact centre platform | Businesses wanting chat and voice AI in one contact-centre platform | London |
| Fifty One Degrees | AI consultancy | Companies with no in-house AI engineers | London and New York |
| Antek Automation | AI automation agency | UK small businesses wanting voice agents and website chatbots | Andover, Hampshire |
| Mavera AI | Voice AI assistant platform | UK businesses wanting a custom voice assistant on calls and chat | Nottingham |
How we chose
Four checks, applied to every company except our own:
- They build conversational AI for customer conversations. Chat, voice or both, for real customers rather than internal tools.
- They are UK companies. Founded in the UK or run from a UK office.
- Their website says plainly what they build and who for. Where we could not confirm a fact, we left it out.
- Between them, they cover different buyers. A council, a large airline and a local dental practice need different partners, so the list spans agencies, voice AI specialists, platforms and consultancies.
We say nothing here about anyone's prices, size or results.
1. Fiveleaf
Fiveleaf is a UK conversational AI company that designs, builds and runs AI chatbots and voice agents for customer service.
- Best for: teams that want an agent built, run and improved for them, not another tool to manage.
- What we build: customer service agents on chat, WhatsApp and voice, connected into the systems a business already runs (CRM, billing, ticketing, the phone system).
- Based in: London.
- Website: fiveleaf.co.uk
Conversations that act. A Fiveleaf agent doesn't stop at an answer: it checks the account, raises the ticket, books the visit, makes the save, and hands over to a person with the full history when it should.
We build it into the systems you already run, then we run it for you, month after month, and it gets better because we read every conversation. Broadband is where we learned it: faults, bills, outages, installs and leavers. For a UK fibre ISP, the retention agent has a 71% cancellation save rate on customers coming through our channel.
You can try one of our agents or book a call.
2. The Bot Forge
A UK AI consultancy that builds chatbots, AI agents and enterprise AI systems that the client owns.
- Best for: organisations that want an AI build they own outright, with strategy and governance support around it.
- What they build: chatbots and AI agents, digital humans and retrieval-based AI systems, plus strategy, proofs of concept, integration, maintenance and training. They work across several AI platforms rather than one.
- Based in: registered office in London, with a remote-first team across the UK and Europe. Building AI systems since 2017.
- Website: thebotforge.io
Their case studies cover financial services, healthcare, retail, and hospitality and events.
3. PolyAI
An enterprise voice AI company whose platform runs voice agents for customer conversations.
- Best for: large enterprises that want to automate high volumes of inbound phone calls.
- What they build: voice agents on their own dialog platform and models, with tools to build, run and improve the agents.
- Based in: founded in 2017 by machine learning researchers from Cambridge; offices in London, New York, San Francisco, Belgrade and Toronto.
- Website: poly.ai
The industries they list include financial services, healthcare, hotels, insurance, retail, telecoms, travel and utilities.
4. EBI.AI
A UK conversational AI company whose platform runs AI assistants and live chat, with a long record in local government.
- Best for: UK councils and public services that want an AI assistant their own team can manage.
- What they build: AI assistants on their AI Studio platform, covering chat, live chat and telephony. Their Community AI service lets councils share the answers to the questions residents ask most.
- Based in: UK.
- Website: ebi.ai
Their UK government G-Cloud listing names Barking and Dagenham, Coventry and Watford among the councils they have worked with.
5. Sabio
A customer experience company that advises on, implements and runs AI for large contact centres.
- Best for: large contact centres already on a cloud contact-centre platform that want AI added by a consultancy that knows it.
- What they build: conversational AI, call summaries, channel deflection and workforce management, alongside CX strategy and cloud migration.
- Based in: head office in London, a second UK office in Glasgow, and offices in Europe, Africa and Asia.
- Website: sabiogroup.com
The clients shown on their site include airline, telecoms, energy and financial services brands.
6. Worktual
A UK AI company with a contact centre platform that puts AI chat and voice agents in front of live teams.
- Best for: businesses that want an AI chatbot and voicebot inside one contact-centre platform, or a custom AI system built on their own data.
- What they build: an AI contact centre platform, the Lola chatbot and voicebot, which pass customers to the right team when needed, and bespoke AI systems built around a client's data and workflows.
- Based in: London, with offices in Chennai and Dubai. Founded in 2022.
- Website: worktual.co.uk
There is a telecommunications page on their site covering billing, plan changes and outage updates, so telecoms buyers will find it worth a read.
7. Fifty One Degrees
A UK and US AI consultancy that puts senior engineers inside client teams to ship production AI.
- Best for: growing companies that have no in-house AI engineers.
- What they build: AI agents, voice AI and predictive models, with a conversational AI service focused on phone call automation.
- Based in: London, with an office in New York.
- Website: 51d.co
8. Antek Automation
A UK AI automation company specialising in AI voice agents and website chatbots for small businesses.
- Best for: UK small businesses such as tradespeople, estate agents, dental practices, law firms, salons and restaurants.
- What they build: AI voice agents, website chatbots and workflow automation, plus work on getting businesses recommended by AI search tools.
- Based in: Andover, Hampshire, working with clients across the UK, mostly remotely.
- Website: antekautomation.com
9. Mavera AI
A UK conversational AI platform for building custom voice AI assistants that handle calls, chat and business workflows.
- Best for: UK businesses that want a custom voice assistant answering calls around the clock.
- What they build: voice AI assistants for customer support, sales, appointment booking and order handling, working across calls and chat.
- Based in: Nottingham. Founded in 2024.
- Website: mavera.ai
How to choose a conversational AI company in the UK
The right partner depends less on whose AI is cleverest and more on how the work is split after launch. Five questions sort most of the field.
Do you want a tool, a one-off build, or a service?
A tool gives you software, and your team builds and runs the agent. A one-off build gives you an agent that is then yours to maintain. With build and run, the company that built it keeps running and improving it.
An agent is never finished. Customers ask new things and the business behind it keeps changing. If nobody on your side owns that work, choose a partner who will. There is more on this in how to choose a conversational AI partner.
How deep does the integration go?
A chatbot that can only answer questions from your help pages will deflect some contacts. One that can read the account, raise the ticket, book the engineer or process the cancellation actually resolves them. Ask any AI chatbot development company to show you, on a real system, what their agent does rather than what it could do.
Who runs it after go-live?
Ask who reads the conversations each week, who fixes a wrong answer and how fast. Ask what happens when the agent does not know something. Those answers will tell you more about a chatbot agency in the UK than its demo.
UK data and compliance
Check where conversation data is stored and processed, whether the company signs a data processing agreement, and whether it understands your regulator. In telecoms, Ofcom expects customers to know when they are talking to AI and never to be blocked from reaching a person. An AI voice agent company working in regulated markets should bring this up before you do.
References
Ask to speak to a client running an agent in production today, ideally in your sector. Then ask them what went wrong, and how it was handled.
Where to start
If you run customer service at real volume and want an agent built, run and improved for you, book a call with us. If you would rather have a platform your own team runs, or a consultancy working inside your contact centre, start with the companies above. Their own websites will tell you more than we can.
