SMS and Messaging — Twilio, MessageBird, and Regulatory Compliance

SMS feels ancient compared to push notifications and WebSockets. It's the flip phone of communication channels. And yet — it has a superpower that nothing else matches: near-universal reach and near-guaranteed attention.

Every phone can receive SMS. No app installation required. No browser permission needed. No internet connection necessary. And people read texts. Studies consistently show SMS open rates above 90%, compared to roughly 20% for email.

That reach comes with significant costs and regulations that make SMS a "use when it really matters" channel. Let's understand when that is and how to implement it correctly.

When SMS Makes Sense

SMS is expensive relative to other channels and subject to strict regulations. Use it for:

Two-Factor Authentication (2FA) — The mos