There is no useful single price without specifying the service, usage and integration responsibility. Public prices describe different layers: a native phone add-on, a managed answering service and a developer platform are not interchangeable products.
The following are public page observations reviewed for this report, not negotiated quotations or market averages. Face values are retained in their published currencies; VAT and other tax treatment have not been normalised.
| Option | Public price observation | What it does not establish |
|---|---|---|
| ServiceM8 Phone Connect Plus | £25/month, 500 call minutes and 3p/minute overage; the UK page lists the AI Phone Agent. | The full cost of the underlying job-management subscription, implementation or supervision. (servicem8.com) |
| Moneypenny AI Receptionist | The main UK page advertises a starting price of £49/month. | Included usage, human escalation charges and your integration scope require a written quote. (moneypenny.com) |
| AnswerConnect human answering | Its public plans-direct page lists Growth at £245/month for 250 minutes, no setup fee and £1.75/additional minute. | Confirm the plan is available to your business and obtain contractual billing and tax terms. (answerconnect.co.uk) |
| Vapi developer platform | $0.05/minute hosting, with model costs passed through; support packages are separately presented. | A managed receptionist, complete telephony costs, integration and agency support. (vapi.ai) |
| Retell AI developer platform | Its pricing page advertises $0.07–$0.31/minute for AI voice agents, with component choices and add-ons. | A turnkey UK HVAC deployment or a fixed all-in rate for your configuration. (retellai.com) |
| Custom agency implementation | No sufficiently comparable, independently validated market price was established in this research. | The broad estimates in the supplied brief should not be treated as standard rates. |
ServiceM8 explicitly says Phone is an additional paid add-on and requires a paid ServiceM8 subscription. Its add-on price must therefore not be presented as the whole system cost. (support.servicem8.com)
There is also a useful evidence warning: a separate Moneypenny resources page displays a £25 starting price, rather than the £49 on the main UK page. Resolve that discrepancy through a written quotation rather than selecting the lower figure for a comparison chart. (resources.moneypenny.com)
How do usage and rounding change the comparison?
Use billable units, not merely call counts. AnswerConnect’s public page states that interactions are rounded up to whole minutes, with a stated allowance for some short interactions. Obtain equivalent definitions from every bidder. (answerconnect.co.uk)
Two simple calculations illustrate the difference between a price and a complete business case:
- At 300 billable minutes, the displayed AnswerConnect Growth rates imply £245 + 50 × £1.75 = £332.50 for the monthly plan and overage.
- At 1,000 billable minutes, the displayed ServiceM8 Connect Plus rates imply £25 + 500 × £0.03 = £40 for that phone-plan component, before the separate base subscription and other costs.
These are arithmetic illustrations using published rates—not equivalent service quotations or forecasts of what either supplier will charge your business. Human and AI handling may also produce different billable usage for the same enquiry; measure that in the pilot rather than assuming identical minutes. (answerconnect.co.uk)
What belongs in a first-year cost comparison?
Use this desk-recommended model for each shortlisted option:
First-year cost = setup + migration + training + the sum of 12 months’ operating costs + transition or exit costs that fall within the comparison period.
| Cost line | Question to put to the supplier |
|---|---|
| Setup and discovery | What deliverables and revisions are included? |
| Base software | Does the project require another subscription or a higher tier? |
| Telephony | Who pays for numbers, forwarding, inbound calls and transfers? |
| AI usage | Which components are included, and can rates change? |
| Messages | Are confirmations, follow-ups and long SMS messages charged separately? |
| Automation platform | What happens when usage limits are exceeded? |
| Human escalation | Is coverage included, metered or purchased from another supplier? |
| Monitoring | Who reviews exceptions and detects silent failures? |
| Maintenance | Are API changes, vendor changes and model updates covered? |
| Business changes | What does a new service area, engineer group or workflow cost? |
| Internal effort | How much staff time is required for testing, review and correction? |
| Exit | What costs arise when moving numbers, records or workflows? |
| VAT and currency | What is payable, recoverable or exposed to exchange-rate changes? |
Request quiet-month, normal-month and peak-month scenarios using your own call records. Do not multiply a quiet-month quotation by twelve and describe it as a seasonal business’s annual cost.
Sources cited on this page
- servicem8.com ↗www.servicem8.com
- moneypenny.com ↗www.moneypenny.com
- answerconnect.co.uk ↗www.answerconnect.co.uk
- vapi.ai ↗vapi.ai
- retellai.com ↗www.retellai.com
- support.servicem8.com ↗support.servicem8.com
- resources.moneypenny.com ↗resources.moneypenny.com