Iphone 13 won't send messages to Android phones (send as SMS ON)

Mine is a slightly different issue where my iPhone 13 was not receiving text messages from android phones - whether an individual user or part of a group text. After searching on the web and getting a lot of mildly useful information, the issue actually turned out to be my Sim card needed to be upgraded to a newer version. All the missing texts from android phones came flooding in 15 minutes later! Not one article online mentioned the SIM card as the possible culprit!

I am having the same issue and i went to the Apple store since i just bought a new iPhone 13 pro 3 months ago. They said phone is fine and then i went to T-mobile. They said to call support. Started 2 days ago as I noticed android users in my group messages cannot receive my messages. Then single android users cannot receive my pictures but they do get messages. Its really weird… After spending 2 hrs with tech support and all kinds of resets... the issue is still there. Might be the SIM card which makes no sense but if its not fixed by tomorrow I will have to replace it.  

Update: Someone called back and was able to pass us on to Apple support where they walked us through resetting their network. 

This would have been much easier if they’d have listened and not constantly interrupted with endless speeches about superior customer support… blah, blah, blah. 

We literally spent half a day listening to canned speeches and not getting a word in edgewise.

Get to the point. Isolate the issue. fix the issue. end the call. 

The phone is now fixed. For those who have issues with iPhone texts not being received by Android phones, suddenly, it is probably an Apple network issue. 

7 words for the 7 hours wasted. You’re welcome

Well, I'm not sure. Usually the iPhone->Android issue has to do with iMessage sending via Apple's server, rather than as SMS. Can the Android send to you? Have you tried replying to a message from the Android phone?

Since I have the same issue, I'll reply. In my case, I can receive messages from Android users, but cannot send to them. I have turned off iMessage and rebooted, then tried again with it turned off (as suggested in another thread), but that did not help. I also tried resetting network settings (as suggested in a bunch of "solution posts" for this issue), but that did not help, either. I also tried toggling SMS, to no avail.

I am having the same issue. I can't even call an Android user.

Of 4 phones on my acct; 3 apple and 1 android. nobody is getting texts from one iphone only. 

Nobody knew. She sent an urgent text on Friday when a family member was rushed to the ICU. This was VERY BAD and nobody knew because there was no message failed, etc. 

I've been on the phone w/support for hours. They barely speak engrish (not their problem, but tmobile's) and this problem hasn't even been properly understood. Tech support won't pick up. 

Been a member since about 98.

Seriously thinking of moving on.

So, this issue has been sitting her for a year, and nobody can offer a solution?