The comparison, including the awkward rows
Figures are indicative and vary by country and volume. The last three rows are the ones vendor comparisons tend to omit.
| Dimension | WhatsApp Business | SMS |
|---|---|---|
| Read where it matters | Dominant in Brazil, Latin America, India, Southern Europe | Dominant in the US, Canada, UK, Australia |
| Cost per message | Per conversation window, typically cheaper at volume in emerging markets | Per segment; cheap in the US, expensive in Brazil |
| Two-way replies | Native and expected | Works, but people reply to SMS less readily |
| Rich content | Buttons, images, location pins | 160 characters and a link |
| Setup | Business account, number verification, provider | A number, and in the US a registration process |
| Templates need approval | Yes, before sending outside a 24-hour window | No |
| Approval turnaround | Usually minutes, occasionally days, sometimes rejected without a clear reason | Not applicable |
| What breaks at 2am | A rejected or paused template stops all sends silently | Carrier filtering, which also fails silently |
The bottom three rows are the reason a WhatsApp-first product is harder to build than an SMS-first one, and the reason most incumbents treat WhatsApp as a secondary channel rather than the default.
The question underneath
Channel choice is usually presented as a preference. It is closer to a demographic fact: in Brazil the phone number in your records is a WhatsApp account, and an SMS to it arrives in a folder that has not been opened this year.
The mirror image holds in the United States. WhatsApp exists there, plenty of people use it, and almost nobody expects their dentist to appear in it. A WhatsApp reminder from a US clinic reads as slightly odd, and slightly odd is enough to reduce a response rate.
So the useful version of this question is not which channel is better. It is: which one does the person you are messaging already treat as the place where real messages arrive.
How WhatsApp template approval actually goes
Described properly, because it is the single largest operational surprise for practices moving from SMS.
- 1
You write the message with placeholders
Fixed text with variables in it. The variables can be a name and a time; they cannot be the entire body of the message.
This is the constraint that catches people. You cannot approve one generic template and then send anything you like through it — the approved thing is the wording.
- 2
You submit it and wait
Usually minutes. Sometimes hours. Occasionally it comes back rejected with a category rather than an explanation.
Common rejection causes: anything that reads as marketing, placeholder-heavy templates, and messages ending in a variable with no punctuation. The last one is a real rule and it surprises everyone.
- 3
Approved templates carry a quality rating
If enough recipients block or report you, the rating drops and the template can be paused.
This is the failure mode nobody plans for. A practice that has been sending fine for months can find its sends stopped because of a run of blocks, and the notification is easy to miss.
- 4
Replies open a 24-hour window
Inside it you can send freely, no template required. This is why two-way conversation is where WhatsApp is genuinely better than SMS.
Design the programme around this: the seven-day message opens a conversation, and everything the front desk needs to say afterwards is free-form and immediate.
None of this is difficult. All of it is work, and it is continuing work rather than setup work, which is the part that decides whether a small practice should run it themselves or buy something that runs it for them.
The arguments people make
- SMS is universal, WhatsApp needs an app.
- True and largely irrelevant in the markets where WhatsApp wins, where installation is effectively universal among adults with a smartphone. It matters at the margins — older patients, feature phones — which is the argument for a fallback rather than for a channel choice.
- WhatsApp is cheaper.
- In Brazil, usually yes and substantially. In the United States, no: SMS is cheap there and WhatsApp conversation pricing is not obviously better. Cost follows the same regional split as everything else on this page.
- Template approval makes it too rigid for a clinic.
- For reminders it is fine, because reminders are the same message every time with a different name in it — the exact shape templates were designed for. It becomes painful when you want to send something ad hoc to a hundred people, which is a marketing use rather than a reminder one.
- Just use both and let the patient choose.
- The right answer, and more expensive to build than it sounds. Per-patient channel preference, a fallback when the primary fails, and one reply inbox covering both is meaningfully more work than picking one — which is why several products offer both channels and a preference field that nobody fills in.
Questions
Can I send reminders from my normal WhatsApp?
Does WhatsApp count as consent-compliant?
What happens if a patient blocks us?
Is email still worth sending?
The messages themselves
All three touchpoints, written natively in English, Portuguese and Spanish.
Tell me when this exists
In the context field: which channel your patients reply on today.