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

" I also wish that they would have waited to implement it until it was stable."

Who’s they? It’s certainly not Apple as most are not having this issue. I’m certainly not and text my Android friends using RCS without issues. Apple has implemented RCS to comply with the RCS standard, not Google’s customized version. Remember that it takes 3 to tango with RCS: your iPhone, your cellular carrier, and the Android user you are texting.

I don't know where the fault lies. I can accept Apple might not be responsible and I actually really don't care who is. I just want it to work.

I am on T-Mobile

It doesn't matter what the recipient is on. My actual device will use RCS for a while and then it will stop. This is verified by Settings > About > ESIM Carrier. Tapping that shows what is enabled. It will say RCS when RCS is enabled and just Voice & SMS when it isn't.

Most of this has nothing to do with my situation. Like I've said, my device will not hold on to RCS for very long when it gets it and then it defaults back to SMS. I suppose it could be an issue with T-Mobile. I haven't contacted them so far because their support tends to take a long time to talk to and in my experience, they tend not to know anything.

So I was having this issue too, but it looks like it might be the android users! If they have wifi on, it causes my phone to only send in SMS. I can receive rcs, but only send sms. If they turn off wifi it will send as rcs. I am on ios 18, iPhone 14 pro max and this has fixed the intermittent issue!

This thread is a total mess. There are different things going on and they appear to be the same because the results are the same.

There are those that can only send RCS to certain recipients.

There are those who keep losing the ability to send RCS to anyone. I am one of those people.

I have T-Mobile. On my phone, I go into Settings > General > About, and tap on Carrier. When RCS is available, it shows Voice, SMS & RCS. When RCS is not available, it shows Voice & SMS. This has nothing to do with the people I'm sending messages to. The problem is on my end.

If I turn off and restart my phone, RCS comes back for a while, usually less than a day, and then it is no longer available again. If I go into Settings > Cellular and turn off my line and turn it back on using the Turn On This Line switch, it comes back for a while and then it is no longer available again. These are the only two methods I've found to fix this issue. Turning RCS off and on again using the setting in Settings > Messages does nothing because it has nothing to do with the Messages app. It has to do with my phone's connection.

My question is, what is causing the issue? Is it T-Mobile? Is it something to do with Apple? I have no idea how this all works under the hood.

It has been a never ending source of frustration for me since Apple made this available. I usually wait to update my phone to the latest iOS to let them iron out all of the inevitable bugs but I made an exception for iOS 18 because I was so excited about RCS being available and at least for me it has largely been unavailable without BS workarounds that never work for more than a day.

It's actually pretty simple. Your phone can only send a message, SMS or RCS through the carrier and if RCS is at times missing, it means your carrier doesn't have RCS available at the time you want to send the message. RCS is NOT an Apple Service. But it is a new service through iPhone, which the carriers have to implement on their end AND make stable on their end.

I honestly don't get why it matters that much? Whether a message is sent via SMS or RCS, as long as the message is delivered, seems most important to me. Maybe you can help me understand from your point of view, why it matters so much?

"It has been a never ending source of frustration for me since Apple made this available"

So why did you want it in the first place? Because you believed the hype about RCS as the be-all, end-all of texting? It’s not.

Thanks for this explanation. It is a helpful comment and actually gives me the information that I need.

It really doesn’t matter that much. I just like the idea of the tapbacks and being able to send videos that aren’t compressed garbage and seeing the typing indicators. Everything that works iPhone to iPhone but doesn’t with SMS. As for just sending a message, it doesn’t matter at all. SMS has always worked fine for that.

You're welcome. I haven't seen any mention that RCS doesn't compress videos sent through messages. I suppose it's possible, but I can't find anything to support this? And you mention Tap Backs. Can you elaborate on how you believe RCS is part of that?

My wife has a Samsung Galaxy Fold so we’ve been playing with it when it works. When I send videos though SMS, they’ve always been garbage and unviewable. When I send them through RCS, they look perfect. When I tapback with RCS turned on, she can see it. When on SMS, it comes up as a separate icon.

Thanks for your comment, but I don't agree with you in total. Apple opened the channel or service to RCS on iPhone. It's in the hands of carriers to use that channel reliably. Just like Apple doesn't send or deliver SMS/MMS. Carriers do.

Look into the GSMA’s Universal Profile specification that defines RCS messaging. It is not as simple as device makers just clicking a box to accept RCS. Devices need to make several technical changes to support RCS including:

Supporting IP Multimedia Subsystem (IMS) core, which is required for handling rich communication traffic.

Adopting new APIs for messaging and network protocols, ensuring consistent functionality.

And adding encryption during data transmission using Transport Layer Security (TLS).

varjak paw wrote:

says that they support RCS only on select Samsung phones.

And no cross-carrier compatibility.

I’m having the same problem 🙃

I've just got off the phone from O2 UK

They have not got RCS messages enabled at the moment but it's coming soon

I agree @fuzzylobes there’s something else going on.