There is now a one-word answer to whether a Messages thread is private. Apple’s iPhone guide for iOS 27 says that “when a conversation is end-to-end encrypted, you see Encrypted at the top of the conversation”, and that if the word is absent, the messages in that thread are not protected as they travel.
Apple gives SMS and MMS as its examples of threads without the label. The same page also spells out, for the first time in this guide, when a green-bubble RCS conversation can be encrypted and when it cannot.
What the label is telling you
Apple’s full sentence is worth having in front of you: “For security, messages sent using iMessage are end-to-end encrypted as they’re sent, and you can also use Contact Key Verification. When a conversation is end-to-end encrypted, you see Encrypted at the top of the conversation.” If the indicator is not there, Apple says the messages “aren’t protected from being read by others as they’re sent”.
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The guide shows a small lock icon in front of the word, so what you are looking for is a lock and the word Encrypted, not a banner. Apple does not say the indicator itself is new in iOS 27. The documentation is: the iOS 26 version of this page, titled About iMessage, mentioned end-to-end encryption and Contact Key Verification and said nothing about an on-screen indicator at all.
Blue, green and the send button
Bubble color still tells you which service carried the message, and that is a separate question from encryption. Apple’s wording: texts between people using iMessage on Apple devices “appear in blue bubbles”, while “SMS, MMS, and RCS messages appear in green bubbles”. The send button follows the same rule. A blue send button means iMessage. A green one means SMS, MMS or RCS.
So blue means iMessage, and iMessage is end-to-end encrypted. Green means one of three different services, only one of which can be encrypted at all. That is why the word at the top of the thread is more useful than the color.
RCS can be encrypted, and it takes two carriers
The iOS 27 page adds an About RCS section. Apple describes RCS as “a carrier-provided messaging service you can use in the Messages app on your iPhone to communicate with people on Apple and non-Apple devices”, and says that when iMessage is not available, “Messages can send your text as RCS instead”.
The points that matter for privacy:
- “RCS is provided by your cellular carrier, not by Apple. To use RCS, you need a text-messaging plan from a carrier that supports it.”
- “RCS supports read receipts, typing indicators, Tapbacks, inline replies, and high-resolution photos and videos.”
- “RCS conversations can be end-to-end encrypted when both your carrier and your contact’s carrier support encrypted RCS.”
Both carriers, not one. If your network supports encrypted RCS and the person you are texting is on a network that does not, the condition Apple states is not met. Apple names no carriers on this page, so there is no published list to check yourself against, and the guide does not say whether the Encrypted label appears on an encrypted RCS thread. Treat the label as the test and the carrier question as the reason it might be missing.
If a conversation has to be private
Keep it on iMessage and confirm the word Encrypted is there before you send anything sensitive. For a step beyond that, Apple points to Contact Key Verification on the same page, which is the feature that lets you check you are really messaging the person you think you are rather than someone who has slipped in between.
If the label is missing and the other person is not on an Apple device, encryption on that thread depends on both carriers, and neither you nor Apple controls that. Apple documents no setting that forces it, so the honest reading is that the thread is not protected until the indicator says it is.
Where to look on your iPhone
Open Messages, tap the conversation, and look at the top of the screen above the thread, for a lock and the word Encrypted. Apple’s instruction is that simple, and it takes a second. It also answers the question that bubble color only ever hinted at.
Messages was one of several apps rewritten for the September 14 release. Our iOS 27 release rundown covers the rest, and the CPA2 security requirements are the other privacy change worth reading this week.
