Desktop app
WhatsApp and SMS on the same number
How Cradle WhatsApp and Cradle SMS relate to each other on your numbers, and what changes when one number supports both.
Important
WhatsApp is in private beta. We expect a general release of WhatsApp in mid-2026.
WhatsApp and SMS are two different channels with different rules, even when they live on the same Cradle number. This article explains how Cradle handles each one and what that means day to day.
How the two channels differ
Both run from the messaging area in the Cradle desktop app, but they behave differently behind the scenes.
- SMS runs over the mobile phone network. Cradle SMS is country-confined: an AU SMS number messages AU mobiles, a UK SMS number messages UK mobiles. SMS requires a dedicated Cradle-provisioned mobile number, separate from your main voice number. See Why does my Cradle SMS need a separate number?.
- WhatsApp runs over WhatsApp's internet messaging network. Most Cradle numbers can be enrolled as a WhatsApp sender, including a landline. Reach is global once enrolled. There's also a 24-hour reply window that doesn't apply to SMS. See The WhatsApp 24-hour window.
What "the same number" looks like in Cradle
The number a customer reaches you on depends on how they contact you, not which channel you'd prefer to use.
- A customer texts your SMS number. That's an SMS thread. It sits in your messaging area as SMS.
- A customer messages your WhatsApp-enrolled number. That's a WhatsApp thread. It sits separately in your messaging area as WhatsApp.
- The same person reaches you both ways. You'll see two threads, one per channel, even if it's the same customer. WhatsApp matches by phone number and SMS matches by phone number, but they're different conversations.
If a customer asks you to "text me on WhatsApp instead" or "switch this to SMS", you'd start a new conversation on the other channel rather than converting the existing thread.
When the same Cradle number handles both
Most teams have their SMS number and their WhatsApp number set up separately, because the SMS side needs a dedicated mobile and WhatsApp can run on a wider range of numbers. If your org has both turned on for the same Cradle number, picking SMS vs WhatsApp is something you choose when you start a new outbound conversation.
In a new-message flow, you'll choose the channel before composing. Inbound threads are still tagged by the channel they arrived on, so you can tell at a glance which is which.
Which channel to pick
If you're not sure which channel a customer would prefer, a useful rule of thumb:
- SMS is universal on mobiles in your country. Almost every customer can receive an SMS without needing an app.
- WhatsApp is the right pick for customers who use WhatsApp day-to-day. Once you're inside the 24-hour reply window, the experience is closer to a chat conversation.
Ask the customer if they have a preference. Many firms keep voice and SMS for transactional updates and use WhatsApp for client conversations that run over multiple days.