SMS vs WhatsApp for UK businesses
"SMS or WhatsApp?" is really two questions — one about how you reach people, one about the job the message does. They're not the same tool, and for a lot of business messaging SMS is the simpler, more reliable choice. Here's an honest comparison so you can decide.
Where SMS wins
- Universal reach. Every UK mobile receives SMS — no app to install, no account, no opt-in to a platform.
- No login, no friction. A reminder or a code lands on the lock screen and is read in seconds.
- Perfect for one-way, time-critical messages. Confirmations, dispatch updates, appointment reminders, verification codes.
- Simple to send at scale. One API call per message; no template pre-approval process to manage.
Where WhatsApp fits
WhatsApp is strong for rich, two-way conversations — media, threaded back-and-forth, chat-style support. If your use case is genuinely conversational, it has a place. It also comes with more setup: a Business API, template approvals, and a session/conversation pricing model.
A quick side-by-side
| SMS | ||
|---|---|---|
| Reach | Every mobile | App users only |
| Setup | API key, send | Business API + template approval |
| Best for | Alerts, reminders, codes | Rich two-way chat |
| Read behaviour | Fast, lock-screen | In-app |
Being straight with you
Bremlio does SMS and OTP — we don't offer WhatsApp today, so we won't pretend otherwise. If your messaging is transactional — the reminders, confirmations and codes that just need to arrive — SMS is very likely the right fit, and it's what we do well. If you genuinely need conversational WhatsApp, use a dedicated WhatsApp provider for that part.