Unable to receive 2FA codes via text with cellular network after updating to iOS 18.1.1

I have the same exact issue. I noticed this back on 11/23 when I tried to make a purchase that required an OTP code to make payment. Most people are not going to have a problem because this is exclusive to wifi calling / VPN that is needed with AT&T. I have the same situation in that I am many miles away from cell service and I work on wifi-calling all day long. So SMS short codes on Wifi calling is the issue. If you have any type of cell service there is no issue. But if wifi calling is the only signal you have you are SOL. I am wondering if this is related to 18.1.1 or the new RCS capability. From what I read RCS is not available through the wifi calling VPN service. But I am struggling trying to get 2FA changed to other methods than an SMS short code.

AT&T network engineers are working on this problem. It is occurring with text messages from banks and other companies. Texts do not come through on WiFi but as soon as you get a cell signal from a tower they come through. SMS and iMessages do come through. A selective issue me thinks.

I'm having the same issue. I have no phone service where I live right now, so I have to rely on wifi calling / texting to receive very important messages. I can send SMS (*SMS*, not RCS or imessage) to friends and receive their SMS as well. I can also call anyone and receive calls from anyone. Somehow, I cannot get any 2FA SMS from banks or Amazon. Basically none of the SMS short codes. Incidentally, all of the spams and advertisements SMS also stopped coming so it probably has something to do with how Apple implemented their spam filter for wifi texting.

And as others have said, I also received 2FA SMS just fine before 18.1.1.

I really need to get SMS from some services right now but it's impossible...

I have no idea what you're talking about. Because I could still receive their 2FA codes over wifi 3 weeks ago before the 18.1.1. update. Also, my friend abroad who is on Verizon has to use wifi calling to receive 2FA codes from Chase / Amazon / Ebay, etc. and it's still working for him. So it probably has something to do with AT&T and this new iOS update, and not about financial institutions changing their protocols on 2FA codes.

Understood…I think though we are troubleshooting 2 different things. Turning off Cellular also turns WiFi calling. The VPN is not established to ATT without Cellular enabled. So to really be able to test is to have zero cell coverage and have WiFi service that allows WiFi calling VPN to ATT to establish. When the VPN is established you have AT&T WiFi in the upper left portion of the phone screen.

The reason I know it is a VPN as network packet captures indicate that it is an IPSec tunnel established from the device to ATT address space.

Because 2FA is used by many banking apps, and other services, it may be restricted to actual reception of text/messages. Scammers/hackers are finding ways to intercept these high security texts and VoiP is a potential weakness.

I’m not sure if the carrier may be rejecting the message or the device or sender.

I also have a case with AT&T on the issue, but was told that it will be a while as cases like this are not quickly resolved. I was hoping that the 18.2 version that is coming in a week or so will fix it or I would have to down grade to 18.1 to see if the problem is resolved.

It’s a simple search or two. Google do banks permit 2FA codes over WifI. You find the answer is no. Don’t believe Google, OK, call your banks IT or fraud department. They’ll confirm.

Then Google, who provides SMS service? The answer will be cellular carriers. Don’t believe Google, OK, ask your cellular provider.

Could an update from cellular providers been in the last update? Yes, some (all?) cellular providers will occasionally piggy back software and firmware updates with iOS updates.

But many times they are pushed to your device separately. You can always walk into your provider’s store and ask to have your device updated.

Are you saying that all of a sudden the vpn to ATT (aka WiFi calling) is no longer a secure method of communication for these codes? WiFi calling is not just WiFi …it is a vpn to the carrier in leu of a 5G single.

a device is a device. If the VPN for wifi calling is not secure enough then the cellular signal is just as bad. Not sure why it is just now happening. Btw it is not just banks. Lowes order status is a problem for me as well as a Deloitte site yesterday. I have never received an SMS message without WiFi calling enabled.

Until the carriers can fix the coverage maps WiFi calling ( vpn to carrier) is a necessity.

I’ve said that it’s likely a cellular provider issue in other threads about this issue. I agree, that there are multiple causes for this issue affecting some users.

Here’s my tests. I live in a large urban area and have AT&T service. I daily log into multiple financial (banks, investment, retirement accounts). I worked in the industry, just habit. If I turn off cellular, some websites I don’t get 2FA code to log in. Turn cellular on here come expired codes.

I’ve got WiFi enabled, but some services aren’t using it. Why? I don’t know specifically why, but from industry chatter, webinars, it looks to me that WiFi is an issue for some institutions. It could be for large retailers as well. A man in the middle on public WiFi could be a concern. I don’t know.

What did AT&T say? Why can’t you receive text message over cellular?

I can confirm as well. Yesterday I noticed the RCS status is now activated and I was able to get a code from an institution that had failed a day earlier as well as other that had failed.

I’m saying what I said. Google it, call your banks. I know what I know from working in the finance industry and attending security webinars. Could some banks use VoIP, I suppose so. In some markets, small banks could be forced to.

My AT&T account has 2FA, one guess how it’s sent. Just find an authoritative source. I Googled it and can’t find one.