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Best AI Phone Agent Builders in London (2026)
If you run a small business in London and want a phone agent built around you rather than software you configure yourself, your main options are a done-for-you service such as DeskAgent or UpZilo, a bespoke developer such as Softomate Solutions or GlluzTech, or an enterprise platform such as PolyAI. Published prices range from £99/month plus setup on a 12-month agreement (UpZilo) and £125/month with no setup fee or contract (DeskAgent's Phone Agent) to bespoke builds from £8,000 plus monthly care (Softomate Solutions), with bOnline's £10/month add-on as the low-cost, do-it-yourself alternative.
Disclosure: this article is written by Monty Gordon, founder of DeskAgent, which is the first entry below. Every other company is described only from its own public website, checked on 27 October 2026. Prices change, so check with each provider before you decide.
How do London's AI phone agent builders compare?
| Provider | Approach | Starting price (as published) | Best for |
|---|---|---|---|
| DeskAgent | Done-for-you AI front desk: phone, WhatsApp, web chat and email | Phone Agent £125/month, no setup fee, no contract | UK service businesses that want it built and run for them |
| Softomate Solutions | Bespoke voice agent development | From £8,000 one-off ex VAT, care from £499/month | Complex builds wired into your own systems |
| GlluzTech | Custom AI agents, including voice and telecom agents | Pilots about £3,000 to £8,000; then about £200 to £600/month | Businesses wanting a scoped pilot first |
| A1 Automation London | AI voice agents on platforms such as Vapi, Bland AI and Synthflow | Not published for voice agents | Inbound and outbound call automation |
| UpZilo | Done-for-you AI receptionist, sold alone or with marketing | £99/month + £299 setup, 12-month agreement | Firms happy with a 12-month term, or wanting marketing too |
| bOnline | Off-the-shelf AI receptionist on a London VoIP phone service | £10/month add-on to a bOnline plan | Low-cost, do-it-yourself call answering |
| PolyAI | Enterprise voice agents for large contact centres | API from 2 US cents per minute; platform on request | Large brands and high call volumes |
1. DeskAgent - Monty Gordon
I'm Monty Gordon, the founder of DeskAgent, and I'm based in London. For more than five years I've run digital operations for UK trades, maintenance and facilities businesses through my agency, MG Digital Services, and I've built more than 40 websites along the way. Again and again I saw the same problem: plenty of enquiries coming in, and too many of them going cold because nobody was free to pick up. So I built the front desk those businesses needed.
How a build works with me
- Before we even speak, I build a demo agent from your website, so on our free 30-minute call you hear your own business being answered.
- We train it properly on your services, prices, areas, opening hours and what counts as urgent for you.
- We test it together before a single customer hears it.
- We go live on your existing number through call forwarding. The Phone Agent is live in under two weeks, and on the 3-month pilot most of the full system is running within the first week.
- You stay in control from WhatsApp. With DeskAgent HQ you check today's leads or ask for a change just by sending a message.
It isn't just a phone agent: DeskAgent has four agents - Phone, WhatsApp, Web and Inbox - that share one brain, so a missed call can carry on as a WhatsApp chat without the customer having to repeat themselves, and you run the lot from WhatsApp with DeskAgent HQ. And every agent is honest that it's an AI if anyone asks.
Pricing: Phone Agent £125/month and WhatsApp Agent £125/month; Web Agent and Inbox Agent £85/month each; Full DeskAgent, with all four plus HQ, £285/month. The 3-month pilot is a one-off £500 for the full build and three months live, then £285/month if you keep it. Single agents have no separate setup fee, and there's no contract. See full pricing.
Already working: the same agents already answer enquiries for London service businesses in commercial pest control, property maintenance, cleaning and facilities management.
Worth knowing: DeskAgent Ltd was set up in December 2025, so it is the newest company on this list, and because every build is done for you it takes days rather than minutes to set up. There's no free trial - you get a free demo built on your business instead.
Book a free 30-minute demo with Monty
2. Softomate Solutions
Softomate Solutions is a software and AI development firm in Stanmore, north-west London, offering AI voice agent development for London and wider UK businesses.
What they build: Custom AI voice agents that answer inbound calls, qualify callers, book appointments and run outbound follow-up, with results recorded in your CRM. It also sets up AI receptionists on GoHighLevel and builds chatbots and automations.
Pricing (as published): Bespoke voice agent development from £8,000 for a first implementation, with optional monthly care from £499/month; mid-market builds typically £25,000 to £45,000; a GoHighLevel receptionist setup from £2,000 plus a monthly package from £99 plus usage. All quoted excluding VAT, with licences, hosting and usage extra.
Best for: Businesses with complex needs that want a bespoke agent integrated with their own systems.
Worth knowing: The most transparent published pricing among the bespoke builders here, but a much higher upfront cost than a subscription service.
3. GlluzTech
GlluzTech (Glluz Tech AI) says it is London-based and happy to meet in person for scoping. Its site lists no street address, and we could not match it to a Companies House record, so ask who you will be contracting with.
What they build: Custom AI agents, including voice agents that handle inbound calls 24/7 for appointment booking, lead qualification and customer queries, and telecom agents for high-volume inbound and outbound calling.
Pricing (as published): Pilot projects typically from £3,000 to £8,000 depending on integrations, then ongoing monthly costs from £200 to £600 for infrastructure, model usage and maintenance.
Best for: Businesses that want to start with a scoped pilot before committing to a bigger build.
Worth knowing: Its site lists no street address; pricing is published as typical ranges rather than fixed packages.
4. A1 Automation London
A1 Automation London is an AI automation agency with location pages for Canary Wharf, Croydon, Barnet, Chelsea and Hackney.
What they build: AI voice agents for inbound call handling, outbound calling campaigns, appointment confirmations, lead qualification, customer support and payment collection, built on platforms it names as Vapi AI, Bland AI and Synthflow with ElevenLabs voices.
Pricing (as published): Not published for voice agents - it offers a free call. Its general automation plans are listed from £299/month, but none of them includes voice agents.
Best for: Businesses that want both inbound and outbound call automation built on established voice platforms.
Worth knowing: It says most clients go live in 2 to 3 weeks. There is no street address on its site, and its FAQ says most callers do not realise they are speaking with an AI - if you want callers told they are talking to an AI, ask for that to be built in. Get a fixed quote that includes platform and call costs.
5. UpZilo
UpZilo describes itself as UK based and sells "Growth Systems" for service businesses, with client testimonials from Croydon and Purley.
What they build: Respond 24/7, a done-for-you AI receptionist that replies across phone, WhatsApp, website chat, Instagram and Messenger. It is sold on its own or alongside websites, SEO and ads, and its target industries include builders, plumbers, roofers, clinics and removals firms.
Pricing (as published): £99/month plus a £299 one-time setup fee on a 12-month agreement, including up to 300 digital conversation sessions and 100 incoming AI telephone minutes a month.
Best for: Service businesses happy with a 12-month agreement, or that want marketing from the same company.
Worth knowing: UpZilo says most Growth Systems launch within 2 to 6 weeks. Check the 100 included phone minutes against your call volume.
6. bOnline AI Receptionist
bOnline is a business phone (VoIP) provider based at Grosvenor Gardens in London. It is not a custom builder - we include it as the low-cost, off-the-shelf London alternative.
What they build: An AI receptionist add-on that answers calls on your bOnline line 24/7, from the first ring, with calendar booking. You set it up yourself, and bOnline says no tech skills are needed.
Pricing (as published): £10/month as an add-on to any bOnline plan, or included in its AI Hero plan from £29.95 per user per month + VAT. Free trial with no card.
Best for: Small businesses happy to run their phones through bOnline and configure the AI themselves.
Worth knowing: You need a bOnline phone plan; the AI is phone-only, and call allowances are not published.
7. PolyAI
PolyAI is a voice AI company with a London office at Sheldon Square, alongside offices in North America and Europe. Its customers named on its site include large brands such as NatWest.
What they build: Enterprise voice agents for large contact centres, with data residency options in the US, UK, EU and APAC.
Pricing (as published): Its API is priced from 2 US cents per connected minute plus model usage; pricing for the full platform is on request.
Best for: Large organisations with high call volumes - included here for contrast rather than as a small-business option.
Worth knowing: Built for enterprise contact centres, so it is unlikely to suit a small service business.
How did we choose these builders?
We looked for companies with a public London presence and a public website that offer AI phone or voice agents, and described each one only from what it publishes about itself, checked on 27 October 2026. We left out firms whose sites do not mention phone or voice agents or that are not based in London. We have not hired each builder ourselves, so ask for a demo built on your business before you choose. We will refresh this list every month.
FAQ
How much does a custom AI phone agent cost in London?
It varies widely with how bespoke the build is. Among the London providers here, published prices run from £99/month plus a £299 setup fee on a 12-month agreement (UpZilo) and £125/month with no setup fee or contract (DeskAgent's done-for-you Phone Agent), through pilots of about £3,000 to £8,000 plus £200 to £600 a month (GlluzTech), to bespoke development from £8,000 plus care from £499/month (Softomate Solutions). Enterprise platform PolyAI publishes per-minute API pricing, with full platform pricing on request.
Should I get a custom-built phone agent or an off-the-shelf AI receptionist?
Off-the-shelf tools are cheaper and quick to switch on, but you set them up and tune them yourself. A custom or done-for-you build costs more, but someone who knows phone agents trains it on your business, connects it to your systems and tests it before customers ever hear it. If calls are your main source of work and you have no time to fiddle with settings, a built-for-you agent usually pays back faster. Our comparison of the best AI receptionists in London covers the off-the-shelf options.
How long does it take to build an AI phone agent?
It depends on the builder and how much needs connecting. DeskAgent's Phone Agent is live in under two weeks, A1 Automation London says most clients go live in 2 to 3 weeks, and UpZilo says its Growth Systems typically launch in 2 to 6 weeks. Bespoke projects that connect to CRMs and booking systems usually take longer.
Will a custom phone agent work with my existing number and systems?
Most builders keep your existing number by forwarding calls to the agent. Connections to your calendar, CRM or job-management software depend on the builder and the system, so ask exactly which integrations are included and who maintains them once the agent is live.
What should I ask an AI phone agent builder before I sign?
Ask for a demo built on your own business, the full monthly cost including call minutes and usage, the contract length, who owns and maintains the agent, how you request changes, how urgent calls reach you, where call data is stored and whether the agent will always admit it is an AI if asked.
Want to hear a phone agent built for your business?
Ring +44 20 7101 0617 and DeskAgent's own Phone Agent will answer. Or book a free 30-minute demo and I'll build a demo agent from your website before we speak. You can also see how DeskAgent compares with other AI receptionists.
Before you speak to any builder, our guides to AI receptionist pricing in the UK and virtual receptionist vs AI receptionist will help you ask the right questions, and capturing leads from missed calls shows what a phone agent should do for you on day one.
