SMS is the highest-attention channel a small business has. People read texts, quickly, and they do not read email that way. Twilio is the standard way to send them programmatically, and the per-message cost is genuinely trivial. The thing that catches every business building their first SMS automation is not the price or the API — it is that sending business text messages to US numbers now requires registering your business and your message templates first, and doing that badly means your messages are filtered before anyone sees them.
The pricing model in one paragraph
Twilio has no monthly platform fee. You lease a phone number for a small monthly amount and pay per message sent and per message received. That is the whole model, and it is the right shape for a small business — a month where you send nothing costs you the number lease and nothing else.
What Twilio costs
| Tier | Listed price | What you get |
|---|---|---|
| US long-code SMS, outbound | $0.0083 per message | Per segment sent |
| US long-code SMS, inbound | $0.0083 per message | Per segment received |
| US local phone number | $1.15/month | Per number leased |
Twilio is pure usage billing — no monthly platform fee. Carrier pass-through fees and A2P 10DLC registration costs are billed separately and are not included above. Source: the vendor’s own pricing page, read August 5, 2026. Prices change — verify before you commit.
A2P 10DLC: the step that blocks people
If you are sending to US numbers from a standard local number, you must register under the A2P 10DLC framework — Application-to-Person messaging over 10-Digit Long Codes. This is not a Twilio policy. It is a requirement the US mobile carriers imposed, and every provider has to implement it.
Registration involves three things: registering your business (legal name, tax identifier, address), registering a campaign describing what you will send and how people consent to receive it, and getting your number associated with that campaign. There are one-time and recurring carrier fees involved, billed separately from message costs, and approval is not instantaneous.
Unregistered or poorly registered traffic gets filtered by carriers — often silently. Your automation reports success, Twilio reports the message accepted, and the customer never receives it. Because there is no error to catch, businesses can run a broken SMS workflow for weeks. If your texts are "sending" but nobody replies, check registration status before you debug anything else.
The practical implication: budget days rather than minutes for the first SMS automation, and register before you promise anyone the feature is live.
The automations that justify the setup
1. Missed-call text-back
An unanswered inbound call automatically triggers a text: "Sorry we missed you — what do you need and we'll call back." For any business where the phone rings while people are on jobs, this is the highest-return SMS automation there is. The alternative is that the caller rings the next business on the list.
2. Appointment reminders with confirmation
A reminder the day before, with a reply to confirm. Twilio's inbound webhook makes handling the reply straightforward, and an unconfirmed appointment becomes a task for someone to call. See the scheduling side of this for how the booking end connects.
3. Speed-to-lead acknowledgement
A form submission gets a text within seconds saying you have it and when you will call. This does not replace calling; it buys you the twenty minutes before the customer starts contacting competitors.
4. On-the-way notifications
Status change to "en route" sends a text with a rough arrival window. Removes the "where are they" call from your day and materially improves how the visit is perceived.
5. Review requests
Sent by text after job completion, with a direct link. SMS response rates for review requests are not comparable to email, and reviews compound into every future enquiry.
Compliance is not optional
SMS is regulated more tightly than email, and the penalties are real. The rules that matter operationally:
- Get consent, and record it. Store when, how and for what the customer agreed to be texted. A checkbox on a form with the timestamp saved is adequate; an assumption is not.
- Honour opt-outs immediately and permanently. STOP must work, and it must work across every automation you run — not just the one that sent the message. Keep a central suppression list every workflow checks before sending.
- Identify yourself. The first message to a customer should say who you are. They do not have your number saved.
- Respect quiet hours. Automated messages at 6am read as spam and generate complaints, which feed back into carrier filtering.
- Keep transactional and marketing separate. Consent to appointment reminders is not consent to promotions. Mixing them is both a compliance problem and the fastest way to get people to opt out of the messages they wanted.
Twilio, or something simpler?
Twilio is the right choice when you want full control, usage-based pricing with no platform fee, and the ability to build exactly the flow you want. It is a developer product — the API is excellent and there is no drag-and-drop campaign builder.
Choose something else if you want SMS bundled with everything else and are willing to pay for the convenience: GoHighLevel includes messaging natively, and field service platforms handle job-related texting without any of this setup. If your customers are outside the US, or already message businesses on chat, WhatsApp is often the better channel entirely.
Where Twilio wins decisively is cost at volume, and flexibility. If you are sending thousands of messages a month and the flow is specific to how your business works, the per-message economics are hard to beat — provided you have someone who will do the registration properly and build against the API. That is exactly the sort of thing we handle in an agency engagement.