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

Have you confirmed with Verizon that RCS is enabled for your plan and phone? They don't support it on all of their cell plans. Also confirm that they're supporting RCS in an iPhone. As of right now their "Advanced Messaging" page

https://www.verizon.com/support/advanced-messaging-faqs/

says that they support RCS only on select Samsung phones. So this may well be an issue with Verizon, not your phone.

Regards.

Fuzzylobes wrote:

My other lines that family members use iPhones have their RCS Messages work flawlessly. My line is the one with the problem and even under eSIM it shows only Voice and SMS is provided for service and not RCS.

That probably means that your line was not provisioned correctly in the carrier’s network. Call them and request that they either add the feature or reprovision your account.

OR it means that you do not have Cellular Data enabled on your iPhone. MMS and RCS (and Visual Voicemail) require cellular data to work, they cannot use Wi-Fi.

OR it means that you have a corrupt VPN profile.

I’m running iOS 18 on an iPhone 15 Pro Max on T-Mobile.

What worked for me was going to Settings > Transfer or Reset IPhone > Reset > Reset Network Settings.

WiFi Calling was disabled for about 5 minutes, but then activated on its own. After that, I checked my carrier settings under Settings > General > About > Carrier > tap the Carrier button > it’ll change and show “Voice, SMS & RCS”.

I was able to send messages using RCS to my Android friends.

Hope this helps.

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

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:

If you respond in an existing thread that was originally SMS then all added messages in that thread will be SMS. You need to start a new thread with the contact for it to be RCS.

Not sure if this will help but a couple of thoughts.

It’s possible your carrier does not support RCS yet. You can check here: Wireless carrier support and features for iPhone in the United States and Canada - Apple Support

Another issue is that RCS on iPhone does not work with VPNs (yet). Here’s an article that may help explain: https://support.mozilla.org/en-US/kb/rcs-messaging-and-mozilla-vpn

It’s specifically about Mozilla’s VPN, but it’s true for other VPNs too.

Best of luck to you.

RCS has now started working again on my phone. I had numerous calls and chats with Verizon, but I’m not sure anything they did fixed the issue.

The one thing I tried on my end (after reading about similar issues on Android forums) was turning off RCS on my phone for 14 days. On day 15 I reenabled it. I suspect that this might have fixed the issue rather than anything Verizon did.

Lots of people on this post have very different problems with RCS. My issue was that new RCS threads worked, but older RCS threads from before I upgraded my phone did not work. My guess is that there was some kind of per-thread key exchange/authentication that did not properly transition over with the phone upgrade and by turning off RCS for an extended period of time, it forced the phone to reestablish those keys.

The carrier you have may make a difference, but I have iPhone 11 with T-Mobile and am on iOS 18. My messages with android users kept switching between SMS/RCS and I couldn’t figure out why. I did one of the steps someone else suggested which was to tap on the carrier option in the settings to change it to say SMS RCS but I don’t think that does anything because I restarted my phone and it went back to say T-Mobile until I tapped it again. I think it’s just for informational purposes. The fix is to go into messages and turn off “send as text message” and then be sure to turn on RCS. This will eliminate the switching and will now only send messages as RCS to android users. The only issue I can see happening with this is being turned off means when iMessage is not available to send to another iPhone, the message will not automatically be sent as SMS and will delay your message to be sent until iMessage is available again. Unless you go back to the settings and temporarily turn “send as text message” back on. See attached images. I hope this helps.

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!

I have the 15 Pro Max. I updated to iOS 18 within an hour of it being available. My [RCS] messaging worked between my iPhone and an Android until this morning. I checked Settings > General > About > Carrier and only saw “Voice & SMS”. I attempted to resolve the issue by doing a Force Restart. Once my iPhone was back up (after the force restart), my RCS was working again.

My assumption is that my carrier (T-Mobile) must have done some network updates overnight. By doing the force restart, my iPhone was forced to speak with T-Mobile again and update settings.

If you have this issue, before calling your carrier, try a force restart to see if that resolves it. All of the major carriers should support RCS.

Well, if you're on Android, I believe you default to Google's RCS servers (unless the carrier forces you to use theirs), which probably gives Android users a more unified experience.

iOS uses the carrier's RCS servers.

So, if Google wasn't running their own RCS servers, then Android would probably be in the same RCS **** we're in now.

I finally got my work group chat to move away from using SMS/MMS/RCS and now we're using Telegram. We're not looking for secure communication. We just want a group chat with hi-res images and videos and the ability to use rich text. Telegram fits the bill.

If you need to have a group chat with Android users, use ANYTHING ELSE. Don't like Telegram? There's a ton of other free chat clients out there.

EliORojas wrote:

I'm having the exact same issue. The first day it was available, the RCS messages allowed my husband and I to text, send photos, and videos seamlessly ( I have the Iphone 15 pro max and he has the S24 ultra). Yesterday, I was no longer able to message him, everytime I tried it would say it failed and I had to "resend as SMS" Super annoying and frustrating to have to go back after every single message even though I have the setting on for it to automatically send as SMS if RCS or imessage are not available.

As has been explained in the 8 pages of this thread over and over and over and over, RCS depends on the capabilities of your cellular carrier at each of their towers, and not all carriers have the hardware and software to support RCS deployed across their networks. So if it isn’t working contact your carrier and get them to fix it.

It works Android to Android because those phones use Google’s servers, as Android is a Google product. For fairly obvious legal antitrust reasons Apple cannot use Google’s servers, so they have to depend on carriers doing the job.

1st tier Verizon support was able to “restart text service”. It required me to shut off my phone so you can’t call on the line you need to restart. Also I am revolving texts from everyone now but my RCS is still not active. Verizon currently reports RCS outages (iPhone 16 launch broke their server I bet) all over and issued me a refund for the affected period of service outage.

Husband had same issue. Simple fix with Verizon support was to reset network settings: General>scroll down to Transfer or Reset iPhone>Reset>Reset Network Settings. Phone will restart then “waiting for validation” should be gone.