Retell AI comes up constantly in AI receptionist searches, and it is a good product. It is also not a receptionist. It is a developer platform for building voice agents: no monthly plan, no included minutes, no packaged front desk. You top up prepaid credits and pay for what you use, and what you build is up to you.
That makes this a straightforward comparison, as long as nobody pretends the two things are the same shape. Remi is a finished front desk for a UK clinic, salon or trade business. Retell is the toolkit you would use if you wanted to make one yourself.
The short answer
Pick Retell if you or your agency can build, test and maintain a voice agent, and you want full control over how it behaves and what it costs. Pick Remi if you want the phone answered, the appointment written into the diary you already use, the reminder sent, the deposit taken and the unpaid invoice chased, with nothing to build.
It is a build-or-buy decision, not a feature shoot-out.
What each one actually is
Retell gives you the parts: speech recognition, a language model, text to speech, telephony plumbing and an API. You assemble them into an agent, connect it to whatever you use, and run it. There is no monthly subscription and no bundle of included minutes. You buy credits and they draw down.
Remi arrives configured. We connect the diary, load your services, prices and policies, set the voice and the rules, and hand it over. You do not see a prompt, a model choice or a webhook, because none of those are your problem.
Remi is AI rather than a human team, which is a distinction worth being clear about if you are also weighing up a traditional answering service.
How Retell's pricing actually works
You will see "$0.07 to $0.31 a minute" quoted for Retell all over the internet, usually as though it were a price. It is not a price, it is a range, and the range exists because the cost is assembled from components. Quoting a single per-minute number for Retell would be wrong for most configurations.
| Component | Published cost (USD) |
|---|---|
| Voice engine and infrastructure | about $0.055 a minute |
| Text to speech | $0.015 to $0.040 a minute |
| Language model | $0.003 to $0.16 a minute |
| Add-ons: knowledge base, background denoising, PII removal | Priced separately, on top |
| Phone number | $2 a month, each |
| Effective total | $0.07 to $0.31 a minute |
All figures as published by Retell and checked on 24 August 2026, in US dollars. There is no UK entity and no pricing in pounds, so we have not converted these into sterling; exchange rates move and a converted figure would be a guess dressed up as a fact. Treat all of this as a snapshot and check the current rates yourself before budgeting.
The spread is more than four to one, and it is driven by choices you make. A cheap voice and a small model sit near the bottom. A premium voice, a frontier model and add-ons such as a knowledge base or PII removal sit near the top. Here is what that means at real clinic volume, assuming 22 working days a month and calls averaging three minutes:
| Volume | Talk-minutes a month | Retell at $0.07/min | Retell at $0.31/min |
|---|---|---|---|
| Sole trader, 8 calls a day | 440 | $30.80 | $136.40 |
| Small clinic, 20 calls a day | 1,320 | $92.40 | $409.20 |
| Solo GP practice, 50 calls a day | 3,300 | $231.00 | $1,023.00 |
| Four-partner practice, 200 calls a day | 13,200 | $924.00 | $4,092.00 |
Add $2 a month for each phone number. Remi, for the same volumes, is £89, £197, £494 and £1,979 a month ex VAT. Remi Lite is £89 with 500 talk-minutes included and covers the sole trader outright; Standard is £149 with 1,000, and the three larger rows follow the formula £149 + £0.15 × (minutes above 1,000).
We are deliberately not putting those columns next to each other and declaring a winner, because one set is in dollars and the other in pounds, and mixing them would produce a number that looks precise and means nothing. The method behind our side is set out in what an AI receptionist costs in the UK.
What the tables do show honestly is this: at a lean configuration, raw Retell usage costs less than Remi. If price per minute is the only thing you are optimising and you are happy to build and run the agent yourself, Retell can come in cheaper. What those figures exclude is the build, the testing, the monitoring and the person who fixes it at nine o'clock on a Monday. That is the actual trade, and it is worth naming rather than hiding.
Side by side
| Remi | Retell AI | |
|---|---|---|
| What it is | A configured AI front desk | A developer platform for building voice agents |
| Pricing model | From £89/month ex VAT (Lite, 500 minutes); £149 for 1,000, then 15p/min | No base fee; prepaid credits, pay as you go |
| Included minutes | 500 on Lite, 1,000 on Standard | None; pure usage |
| Per-minute cost | 15p beyond the included allowance | $0.07 to $0.31, depending on components |
| Phone numbers | Included in setup | $2 a month each |
| Priced in pounds | Yes | No; USD only, no UK entity |
| Books into | Google Calendar, Acuity, Cliniko | Cal.com and Calendly natively |
| Clinical practice systems | Cliniko, Nookal | Not published |
| Native messaging and booking | Unofficial connector only, no native integration | |
| Reminders, deposits, no-show fees | Yes | Build it yourself |
| Chases unpaid invoices | Yes | Not published |
| Setup | Done for you, one-week free trial | You build it |
Where the booking lands
Retell books natively into Cal.com and Calendly. Both are good scheduling tools, and if that is where your diary lives, this works out of the box.
Most UK clinics are not on Cal.com. Physio and allied health practices run Cliniko or Nookal, salons run Fresha, plenty of practices run Acuity or a shared Google Calendar. Remi books into all of those directly. That matters more than it sounds: if the appointment does not land in the system that holds the clinical record, someone has to re-key it, and the moment a human is re-keying appointments you have not removed the front-desk job, you have moved it.
On Retell you can of course connect anything you like, because it is a platform with an API. That is the whole point of it. It is just work you are doing rather than work you are buying.
WhatsApp and the channels people actually use
Retell has no native WhatsApp integration. What exists is described as an unofficial connector, which is a fair description and not a criticism, but it is not something to build a clinic's client communication on.
Remi's WhatsApp is native and it is where a lot of the value sits. Clients message rather than ring, Remi replies and books them in the thread, and reminders, deposit links and invoice chases go out on the same channel. Across the ten providers we checked in this category, WhatsApp messaging is close to absent, and none of them publishes invoice chasing at all.
Answering the call is the easy half
A modern voice agent holding a natural conversation is no longer the hard part. Both of these can do it. What separates them is everything after the caller says yes.
Remi sends the no-show reminder, takes a deposit at the point of booking, applies your no-show fee, refills a cancelled slot from the people waiting, chases unpaid invoices, wins back lapsed clients and asks happy ones for a review. Those are outcomes, not conversations, and each one is a small piece of revenue that otherwise leaks.
Take one example. A client books, does not turn up, and the slot is gone. A deposit taken at the point of booking changes that outcome, but only if something takes the deposit at the point of booking, which means the payment step has to live inside the same conversation that made the appointment. Bolting it on afterwards does not work, because by then the caller has hung up.
The same is true of refilling a cancellation: the slot is only worth filling in the hour or two after it opens, and that means somebody or something has to notice immediately and message the waiting list. On Retell each of these is a flow you would design, build and keep working.
Retell also gives you nothing opinionated about how a clinic should behave, which is the correct choice for a platform and a cost for a small business. Someone has to decide how far ahead to take bookings, what to do when a caller asks for a clinician who is on leave, when to escalate to a human, and what the agent must never say. Those decisions are the difference between a demo and a front desk, and on a platform they are yours to make.
Where Retell AI is the better choice
Retell is genuinely excellent at what it is for, and there are clear cases where it beats us:
- You are a developer or an agency. If you want to own the prompt, pick the model, tune the voice and change behaviour on a Tuesday afternoon, a platform gives you that. Remi is configured rather than programmable.
- Very low call volume. If you take a handful of calls a week, pay-as-you-go with no base fee is cheaper than any subscription, ours included, and that holds against our £89 entry tier too. There is no arguing with arithmetic.
- You want to control the cost curve. Because Retell's pricing is component-based, you can trade voice quality or model size against cost quite precisely. That is a real advantage for someone who wants to tune it.
- Cal.com or Calendly is already your diary. Native support there means less to connect.
- An unusual use case. Outbound campaigns, screening flows, something nobody sells as a product: the flexible tool wins by default.
If you have the skills and the appetite, building on Retell is a perfectly sensible decision, and you will end up with something shaped exactly to your business.
How to choose
Answer three questions honestly. Who builds and maintains the agent, by name? Is your diary Cal.com or Calendly, or is it Cliniko, Nookal, Fresha, Acuity or Google Calendar? And do you need calls answered, or do you need the outcome: booked, reminded, deposit taken, invoice paid?
If the answer to the first is "nobody", you are buying rather than building, and the rest follows. Our clinic page covers what that looks like in practice, and we have a separate write-up for GP surgeries.