All change for iMessage.

NurPhoto via Getty Images

It’s finally here — almost. Almost 18-months after the FBI warned Americans to stop texting between iPhone and Android, Apple has fixed the problem. Next week, iOS 26.5 should bring encrypted cross-platform messaging for the first time.

But Apple warns this “is not available to all."

That availability affects devices — suggesting not all iPhones will be capable of sending fully secure RCS messages — and also carriers, which affects even iPhones with the upgrade. And it’s this second type of availability that’s the bigger issue.

Forbes‘Increasingly Urgent’—Microsoft Issues Password And 2FA WarningBy Zak Doffman

When you send a WhatsApp message it is always end-to-end encrypted. That’s because WhatsApp controls all “ends” of the chat. The clients (apps) ensure that every message is secure. That encryption can never fall away.

It’s the same when you send an iMessage to other Apple users — the infamous blue bubbles. Every iMessage is fully encrypted. It can’t send messages any other way. If one “end” of the chat is not using iMessage on an Apple device, the bubble is green and it’s clearly noted that this is a text or RCS message.

With Google Messages it’s more complex. If all “ends” are using an updated version of Google Messages, then RCS messages are fully encrypted. But it’s not as clear when that encryption is not running. Users need to check.

That’s even more acute with the new upgrade. Apple’s and Google’s deployment of fully encrypted RCS relies on carriers not apps. The encryption is baked into the protocol, not applied by the iMessage or Google Messages envelope. An RCS chat between an Android and iPhone user could change from end-to-end encrypted to not, depending on which networks the phones are connected to at the time.

In its latest release notes ahead of the new version of iOS going live, Apple says that “end-to-end encrypted RCS messaging (beta) in Messages is available with supported carriers and will roll out over time.” There’s an Apple messaging website, which should carry this detail when it’s available.

All this means that when fully encrypted RCS messaging goes live some time next week, Apple and Google users will still be more secure when using their respective walled gardens. Or when using WhatsApp or Signal. That won’t change.