How to bill your clients for voice-agent minutes
A plan with included minutes, a per-minute rate or a price per call: what fits each client, how to track usage and how much margin you keep.
On this page 8 sections
Three ways to bill
The ways to bill the minutes of a voice agent come down, almost always, to three. What differs is who carries the risk when a month brings more calls than usual.
| Model | How it works | Fits when |
|---|---|---|
| Plan with included minutes | A fixed monthly amount with a bundle of included minutes; minutes beyond it are billed separately as overage. | The client has a steady volume and wants a predictable invoice. |
| Per-minute rate | You charge every minute handled, with no fixed fee. | The client is just starting, or their volume swings a lot from month to month. |
| Price per answered call | One price per call, however long it lasts. | The calls are appointments or bookings: short and alike. |
With a plan of included minutes the client knows what they will pay and you know what comes in each month; overage covers the risk of a heavy month. With a per-minute rate the risk moves to the client, which is why many find it hard to accept at the start: they cannot tell what the invoice will be. With a price per call you carry the risk if calls get longer, so look at the average duration before you set it.
There is no model that is right for everyone. What works is choosing one per type of client and writing it into the proposal, with the numbers in plain sight.
Charge the setup fee separately
Setup (writing the agent's instructions, connecting the client's calendar or CRM, and testing the calls) is work you do once, not a monthly service. Charge it as a one-time setup fee, apart from the plan, and do not hide it inside the monthly price: if the client leaves in month three, you will not have recovered the hours you put in.
A simple way to price it is to count your real hours. As an example, 8 hours of work at US$40 an hour makes a setup fee of US$320. Those numbers are made up: use your own hours and your own rate.
Explain the overage before they ask
Overage is what draws the most complaints. If the client can see which calls produced it, they stop arguing. Two things help:
- Tell them what an extra minute costs in the proposal, not when the first invoice arrives.
- Show the detail: which calls went past the limit and how many minutes they added.
This is how it can look on the invoice of a month in which the client went over their minutes:
October invoice · Techos Caribe SRL
Sample data
- Small-business plan · 500 min included
- US$149.00
- Overage · 42 min at US$0.30
- US$12.60
- Total
- US$161.60
Track usage from a single source
To bill minutes you have to count them, and whoever counts in two places ends up with two numbers. Before you send your first invoice, decide in writing:
- What counts. Answered calls, and what you do with calls that did not complete and with the tests you made yourself.
- How you round. Per second, or up to the minute. Either works, but it has to be in the contract.
- When the month closes. And in which time zone: the client's, not yours.
- What your source is. Your provider's list of conversations. It is the one you can compare against the provider's invoice.
Once a month, compare your count with the provider's. If the difference is more than a couple of percentage points, find the cause before you invoice: it is usually a forgotten test or a call that landed on another day.
Work out your margin per client
Your cost is what the provider charges per minute plus what the language model and the telephony cost; your price is what you charge. These are the list prices we checked on October 19, 2026:
| Provider | What the price covers | List price |
|---|---|---|
| ElevenLabs Agents | The agent platform. The language model is billed separately. | US$0.08 per additional minute; each plan includes a bundle of minutes |
| Retell | Voice infrastructure at US$0.055, voice at US$0.015 with its own voices, telephony at US$0.015, and the language model from US$0.0016 depending on the model. | US$0.07 to US$0.31 per minute, according to its page |
| Vapi | Hosting at US$0.05 per minute on its prepaid plan. Transcription, model and voice are charged separately (in its calculator: US$0.0095 to US$0.0099, US$0.0077 to US$0.0452 and US$0.0146 to US$0.0238). | US$0.08 to US$0.13 per minute, adding those parts (our sum) |
| Twilio (US telephony) | Calls to and from the US and Canada, plus the local number. | US$0.0085 inbound, US$0.0140 outbound, local number US$1.15 a month |
Sources: the pricing pages of ElevenLabs, Retell, Vapi and Twilio, seen on October 19, 2026. The ElevenLabs, Retell and Vapi pages show prices with a $ sign and no currency code; we read them as US dollars. All of them can change.
Your real cost may be lower than the list price. If you pay for a provider plan with included minutes, divide your provider invoice by the minutes you used: that is the number that matters. For the example that follows we use US$0.1285 per minute: US$0.08 for the platform (ElevenLabs' list price), US$0.04 for the language model (our assumption, and also the one Retell's own calculator uses as its example) and US$0.0085 for inbound telephony (Twilio).
A client's margin in a normal month
Sample data
- Revenue for the month (plan and overage)
- US$161.60
- Minutes used
- 542 min
- Cost per minute in this example
- US$0.1285
- Cost for the month · 542 × US$0.1285
- US$69.65
- Gross margin
- US$91.95 (57%)
The same plan gives different margins depending on the month:
| Month | Minutes used | Revenue | Cost | Margin |
|---|---|---|---|---|
| Quiet | 200 | US$149.00 | US$25.70 | US$123.30 (83%) |
| Normal | 542 | US$161.60 | US$69.65 | US$91.95 (57%) |
| Campaign | 1,200 | US$359.00 | US$154.20 | US$204.80 (57%) |
Two things come out of that table. In a quiet month the fixed plan protects you: the client pays the same and uses little. And overage only keeps your margin if you set it well: here we charge US$0.30 for an extra minute, which is more than double the cost. With overage at US$0.20 the margin on those minutes would fall to 36%, against 57% on the included ones. As a rule of thumb of ours, not a law, charge overage at least twice your real cost per minute.
You still have to subtract your payment processor's fee. For example, Stripe Mexico charges 3.6% plus MXN 3.00 per payment with a domestic card, according to its pricing page (seen on October 19, 2026).
Steps to get started
- Choose a model per type of client, not one for everybody.
- Set the included minutes from the data of a real month, not an estimate.
- Set overage at least at twice your real cost per minute.
- Show the client their usage before the invoice, not after.
- Compare your count with your provider's every month, before you charge.
Where teldash fits
teldash is a client portal and billing layer for agencies that sell voice agents. It has not launched yet: it is in development and has a waitlist. Billing with your own Stripe is part of what is being built before launch, and margin per client comes after. This post does not depend on any tool: you can do all of the above in a spreadsheet.
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