Why is RCS not working between my iPhone running iOS 18 and Android?

Not only does the Android phone need to support RCS, but it has to be enabled in their Google Messages app as well.

Understand that Android phones have to support RCS as well. Do all Android phones support RCS. Absolutely no, they do not. “Selected models” of Samsung phones support RCS for example. For RCS to work everything in the chain must support it, the phones at both ends, and the carriers in between.

I’m the only iPhone in my 5-person household. Updated to iOS 18 a few days ago. RCS worked great. Then it didn’t. Then it did. And so-on ever since the update. All 5 phones are on the same cellular network. Different brands (3 Samsung, 1 google). Point is, ATT supports it, their phones support it (because it works some of the time), and everything is activated (again proof is it works some of the time). When my message box changes to SMS, I do not receive their replies until my phone decides to flip back to RCS (it does this on its own randomly while,

for example, I’m in my house the whole time). Yesterday there was a 3-4 hour gap. I also did not receive their calls, or alerts of voice mail messages for several hours - I believe the voice mail alert finally showed up about 4 hours after the texts came through. Coincidentally (?), this morning my son received a very loud weather alert about 30 minutes before I did, and my phone had been on sms during that time.

I’ve restarted my phone multiple times. I’ve turned RCS off and back on a few times. I even went to the ATT store today and they are baffled.

Clearly there are bugs. I hope apple fixes them asap because meanwhile I’m fuming that my husband/kids aren’t replying to me, when all the while my phone is the issue. I have no way of knowing which scenario is correct (because they can’t call me, either, and I’m completely unaware.) Ask any mom of driving teenagers - it is not good when they can’t reach you if there’s an emergency.

As you point out Android RCS uses Google’s servers, iOS iMessage uses Apple’s servers. Apple was pressured into supporting RCS by the tech media and the nerd herd. Apple’s implementation of RCS uses the industry standard which is via the carriers. It is not the perfect solution it was touted to be. IOS users are finding that out now. They were promised otherwise by the tech media. And of course Apple will NEVER use Google’s servers.

I have RCS enabled since iOS 18 update. It broke last week, nothing is fixing it. I think it must be on Apple’s end. For reference, both my phones are on verizon! I’m just trying to send a high quality picture here. So frustrated.

Then you have to wait for your carrier to activate it, or call them and ask if they support RCS. And see the post above yours from amp68.

And you should read this→What is the difference between iMessage, RCS, and SMS/MMS? - Apple Support

Noting especially:

If you aren’t using iMessage, you can use RCS. RCS text messages can be sent to non-Apple devices as well as another iPhone or another Apple device with Text Message Forwarding turned on. With RCS, you can send texts, high resolution photos and videos, links, and more. RCS also supports delivery and read receipts and typing indicators. RCS messages appear in green text bubbles on your device.

Apple’s implementation of RCS is based on the industry’s standard. RCS messages aren’t end-to-end encrypted, which means they're not protected from a third-party reading them while they're sent between devices.

RCS is a carrier-provided service. When your device connects to your cellular network, it communicates with your carrier and their partners to set up RCS. User identifiers are exchanged for your carrier and their partners to authenticate your device and provide a connection. These identifiers could include but are not limited to your IMEI, IMSI, current IP address, and phone number. Your current IP address might also be shared with other RCS users.

To use RCS, you need iOS 18 and a text-messaging plan from a carrier that supports RCS on iPhone. Contact your wireless carrier for more information.



To turn RCS on or off, go to Settings > Apps > Messages > RCS Messaging.

Learn whether your carrier supports RCS messaging on iPhone

This worked for me.

Well, kind of. I am getting some messages from Android friends and other ones aren’t coming in even though I can see the typing indicator.

In addition to turning on the iMessage RCS setting, you also have to have RCS service from the carrier activated. With an iPhone 13, iOS 18, and T-Mobile, this was supposed to be automatic, but that clearly wasn't the case:

I had to re-set my network settings (turn off keychain sharing in iCloud first) to get RCS to become active. (Turn keychain sharing back on afterwards to restore saved WiFi and BT passwords.) I've seen reports that the phone can revert back to just "Voice & SMS" after a few days; it remains to be seen if it's a permanent fix in my case. (This is clearly a carrier issue, and eventually they should get their act together.)

The people you're messaging with have to have RCS working on their devices as well, and on that score the Google Messages app on Android phones is also being uncooperative for some users. They might want to activate the "automatic resend" option:

Good question. I don't know. If I feel adventurous I'll write all my contacts and find out their carrier, phone model, etc. to try to figure it out. Someone said only some Samsung phones on Verizon, so that makes sense.

Allen wrote:

Someone said only some Samsung phones on Verizon, so that makes sense.

As I noted, the article that information is from seems to be wrong. I can see that I have RCS on my iPhone. I didn't even need to contact Verizon. So, I think Verizon hasn't properly updated its website. This calls into question whether the rest of what they said, that there is no carrier interoperability, may also be wrong.

Fuzzylobes wrote:

i have the same issue. What I have learned under the about screen in settings, under sim the IMS only allows for sms and voice. While for some a simple restart fixed the problem apparently, in my case it hasn’t fixed it. I have tried network resets, restarting the phone, called between T-Mobile and Apple which one referred me to the other. Ultimately I even had tried deleting my eSIM and downloading a new one while trouble shooting with T-Mobile and that didn’t fix the issue. Only I haven’t done was factory reset the phone and I won’t do it to then find out that doesn’t work too.

I have come down to it that this has to be a software bug and not the carriers.

Nah. If this was a software bug, it would affect everyone. It's not. Something between you and the carrier hasn't been provisioned correctly. This is so new for iPhone. Give it some time. It's working just fine on my iPhone with AT&T.

Allen wrote:

I have Verizon. RCS reports on in settings. So I tried everyone in my contacts list to send a text. All the iPhone users, it said "iMessage." Almost all Android users it said "SMS." BUT I did find two contacts where it said "RCS" so Verizon must not support it for all Android users.

That isn’t the problem. The problem is that not all Android PHONES support RCS. And those that do need a separate messaging app; it is not built in to Android.

And this the HUGE problem with RCS. It's VERY carrier dependent. Whether you have it or nor depends on your carrier enabling it, the recipient's carrier enabling it, the recipient's phone supporting it, and the recipient's phone having it turned on.

I think Google made a mistake with picking RCS. They should have picked their own data-only end-to-end encrypted protocol like Apple did with iMessages. That totally bypasses the carrier and gives 100% control to Google.

We all should stop using iMessage/SMS/MMS/RCS and a use a third-party data-only app like WhatsApp, Signal, Telegram, or any other app out there. Take yourself and the people you talk to out of the carrier's control.

Also don't forget that Apple's implementation of RCS is NOT encrypted. Apple uses the carrier's RCS servers and not Google's.

I am with T-Mobile. My wife has a Fold 6 with RCS enabled. I enabled RCS and it worked for a while. And then it stopped working. Per instructions in this thread, I reset my network and it started working again. And it worked fine for two days and stopped working again. General > About > IMS status did show Voice, SMS, and RCS and now it just shows Voice and SMS. I could reset the network again to get it back but that’s a pain in the *** workflow that shouldn’t be happening. It was working and then it stopped. Twice.

thatboyGBaker wrote:

I thought I was the only one having the same issue! But I have the iPhone 15 plus…..

I thought we were supposed to have the RCS feature?????? I really hope y’all get this fixed and very fast! If that’s the case, why even blab about the feature in the first place??????

You would find it enlightening to read the thread you just added to. There are 6 pages of comments that address possible reasons RCS may not be working reliably for your iPhone, 90% of them having nothing to do with your iPhone.