Why do my texts keep switching between RCS and SMS on iPhone?

I too experience this problem with a single contact only. I receive their texts as RCS but send to them just standard SMS.

Restarted phone, tested on and off wifi, tested with 5G and LTE. Noticed the "flipping" of RCS to Text in the send window as some reported.

Deleting the Contact (not the message), immediately restored RCS.

The contact is on Verizon, I am on T-Mobile. A OnePlus device.

I am re-adding the entry to my contacts and see if it remains on.

[Edited by Moderator]

Offering a potential solution for the scenario that you are receiving RCS messages from a specific contact, but sending SMS.

1. Make sure they're the last one to send a message and that it came in as RCS (I think this matters for some reason)
2. Fully close Messages app (Close an app on your iPhone or iPod touch - Apple Support)
3. Go into Settings > Messages > RCS Messaging > Toggle off then back on
4. Open Messages app
5. Navigate to the problem contact -- if you're lucky it's fixed/will show RCS in the message box

To be honest this could have been a combination of things -- I tried, in no particular order:

1. The network reset
2. Specifically ordered airplane mode/toggle RCS on and off method
3. Removing/re-adding the contact.
4. Turned off RCS business messages

In the end, a variation on the simple "turn it off and back on" method worked for me, but maybe you also have to try those first. There definitely seems to be some key order of operations depending on the particular flavor of bug you're hitting.

I also tried this today, so no idea how long it will stick -- fingers crossed.

Try this: navigate to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This will remove all saved Wi-Fi passwords, Bluetooth connections, and VPN settings. 

This fixed my issue, I did this when my RCS would flip back to sms momentarily after each sent message.

Turning RCS Business off did not work for me. However the suggesting on resetting the network worked!!! THANK YOU!

This was happening to me too after I woke up to find my phone auto updated. I waited about a day, and then waited for my boyfriend running a Samsung phone to send me a message (making sure it said RCS for it) and I replied back with a photo from my camera roll while connected to wifi. Suddenly it began to work again and my messages towards them are no longer swapping back and forth every time I text.

This is happening to me as well since the ios 18.1.1 update last friday. Sometimes I send a msg and it goes by RCS but mostly its going by sms. My boyfriend's msg are coming to me as rcs but when i reply it sends as sms. Prior to the ios update everything was by RCS both ways with zero issues. I wish I hadn't updated the ios...Apple needs to fix this crap

My iPhone keeps defaulting to SMS instead of RCS. I have SMS disabled and the RCS is active but it still defaults to SMS. I’ve restarted my phone, I have not had any issues with RCS until recently and now I can’t get it to come back.

I just realized that my messages are also sms when I have rcs enabled. I turned my phone off an on, it’s still the same. I updated my phone also so I’m figuring that’s when it happened. It wasn’t like this before the update.

This is happening to me, too — only with one contact however. It started as soon as the new update hit, which auto updated. This needs to be fixed! I keep restarting my phone, sometimes that helps but only for a little bit.

And other weirdness-my daughter (iphone 11) is receiving some of my texts as emails. Also, I sent a pic to a friend (iphone 12 mini) last night. She saw it, then it disappeared from her messages, then it reappeared.

Apple, get this fixed NOW!!

i am having the same issue where i cannot use RCS with my husband(mine keep sending as SMS), but he can text me back with RCS. i am able to text everyone else that has RCS, with RCS. i have no idea why it won’t switch back to RCS for him. i tried turning my phone off and back on. and i am on wifi. Apple please fix this issue.

This is still happening to me on 18.3, to the point where group chats with androids are opening multiple chat threads on the recipients phones. I had to completely disable RCS now or the messages app is pretty much unusable with android recipients.

I now have a group text chat with my coworkers (who I am their team lead) that doesn't function properly on iOS 18.2 unless RCS is on, whereas before iOS 18 that same group chat with the same people worked fine.

Problem is RCS uses more battery and is unreliable in it's current state in iOS.

I’ve been having this very issue with a single contact. I can use RCS perfectly fine with my mum (we both use the same network), but with my boyfriend, it’ll show up as RCS in the message, but then it’ll change to SMS once sent.

I’m not sure whether that’s bc of being on different networks, his phone not supporting RCS, or whether it’s simply bc the data in our area is so bad since they got rid of 3G and Huawei cell towers. I even struggle with iMessage when I’m on data nowadays, every iMessage I try to send when out (and sometimes in the house) sends as a text bc the data is so bad at 4 bars

Same here. My daughter and I are on the same billing plan. She has an 11, I have a 13 mini, she’s the only one that I have difficulty with, and possibly a second person who has a 12, I believe. That person was having an issue too. On New Year’s Eve my messages went through just fine. However, my daughter can text me with no problem, the issue is with my phone sending to hers. I just now tested it and the message went through just fine. Hopefully this is it. It’s so infuriating, I’ve resorted to WhatsApp.