Two-factor authentication SMS verification code

Frequently asked questions about two-step verification for Apple ID - Apple Support

Apple ID: Contacting Apple for help with Apple ID account security

As the Frequently asked questions about two-step verification for Apple ID - Apple Support I attached explains, even if you cannot receive your SMS code, you still must have a recovery key you can use. Further, you may well have entered other "trusted" devices capable of receiving your code.

Have you tried changing the country code setting in the iPhone's telephone number to receive the SMS (submitting your country code if you have not been using it, or omitting it if you've been using it)?

Those "enabling" SMS have to do with your carrier as SMS (including the ones used to activate iMessage and FaceTime) are sent and received via the carrier. Often the problem has to do with proper provisioning of the iPhone by the carrier. As it seems you have set up 2 step correctly, the problem seems to lie in the carrier. I would start there by contacting the carrier.

I'm glad you got the problem sorted out.

FWIW, I use several SIMs from different operators in different countries. I tried getting a phone number from a LatAm operator registered a few months back and it took several tries for the SMS to go through. In the end it worked. But I never had those problems in the US or EU. Go figure!

Hi Fabio,

I am experiencing this issue right now and I am wondering what did the carrier's support people do to fix this problem? I am with Kolbi and suddenly the verification codes stopped coming in. By the way, I know this happened last year. Thanks!

This feature can leave a lot to be desired, particularly if you happen to have a good number of Apple Devices and two users sharing an Apple ID. I know Apple designed the Apple ID assuming a one to one relationship between a user and an Apple ID, but some of us implemented our iPhones and Apps prior to things like "Family Sharing". My experience with Two-Factor Authentication has shown that even as though there is only one Trusted cell number on my Two-Factor Authentication the security code now defaults to one of my other iPhones with the six digit code. This is a real problem in that when you try to visit your iCloud Account on your Mac for example, the Code is sent to an iPhone you don't have at the same location. (again the Trusted iPhone is right there with the Mac) The Authentication Process does give you the option to indicate that The Code Was Not Received ...and then you may or may not receive the Code on the Trusted iPhone ...third try always works. There is also and option, once you have failed to receive the Code that allows you to request a "text". Again this make the Two Step process turn into many additional steps before you can actually sign into your iCloud Account if you want to "Manage your Account" for example.

Now you see just one of the many reasons you should not share an Apple ID. You can still switch to Family Sharing, even if you didn't use it before it was invented.

But the reason you see this is you are also using another feature - Continuity. If you disable Continuity you won't see this issue either.

I addition to what Lawrence has said, use 2 factor AUTHENTICATION instead. It is safer and you can authenticate from any trusted device, either via SMS (on iPhones) or a code via any trusted device (which includes any Apple device running El Capitan or greater and iOS 9 or greater).

And stop sharing your Apple ID. The headaches are not worth it.