The MSISDN is already registered to another IAM user account.
I had an old account with mobile. My phone number and email is attached to my old account. I cannot use the Mytmobile app to log into my account now.
I think I found a workaround.
I kept receiving the error message (The MSISDN is already registered to another IAM user account) and was finally able to sign into the account using the same email when I tied it to my Apple watch number.
Once I could access my account I was able to update everything else.
this is how in stumbled in the fix
logout of your existing tmobile email account
signup for a new account in t-mobile.com with your new **tmobile phone number** not an email address
in the signup you are asked an email address: put the email address of your old tmobile email account, and its password
now you are asked if you want to manage multiple accounts from that email: reply yes
go through verification codes both in email and phone
now you are in your old email account that has the new phone number
Stefano
I had the exact issue. I followed your steps and it worked. I am now able to log back into my account. Thanks a bunch!
this is how in stumbled in the fix
logout of your existing tmobile email account
signup for a new account in t-mobile.com with your new **tmobile phone number** not an email address
in the signup you are asked an email address: put the email address of your old tmobile email account, and its password
now you are asked if you want to manage multiple accounts from that email: reply yes
go through verification codes both in email and phone
now you are in your old email account that has the new phone number
Stefano
I had the same issue. Was previously with t-mobile and just returned and ported my number. Like the other person who resolved this, I'm not sure exactly how I fixed it.
It looks like one solution is to log out and re-register with another email address.
Otherwise, I somehow fixed it by logging into my old account with my email address, went to the community, then followed various "my account" links throughout the website until eventually I got to a different screen that said I could manage multiple t-mobile accounts under one user ID. I apologize for not remembering the exact steps, but there is a way to do it. Hope that helps.
Exact same problem as of 7/12/2022. Almost the same case as those above -- returning customer from an experiment with a different carrier (trying to save a few bucks); well, their [the other carrier] service sucked and I am coming back to T-Mobile after about a 4 month break in service.
But, I have been on the phone with 611 for the past 30 minutes and I have even given them the link to this Community post -- it seems that they *STILL* don’t have a use case in their playbook for how to remedy this.
I will update this post if I ever get resolution.
Ok, so without any help from T-Mobile (611)… sorry to say, but they are nice, chipper, and well-meaning, but some are ill-equipped to handle this (and the word “expert” is thrown around too liberally). So, I finally got access to my account. I ultimately kept clicking on different ways to login (with a user ID, my phone, and of course my old email address that was linked).
Now, I apologize if this gets gray, but sadly I didn’t write down all of these steps that got me access, but here’s a rundown from what I can remember. Through trying to login different ways, e.g., forgot password, or using my phone number, or using an older username I found, I ultimately got to an error page that told me that “the email account you just used is already in use, would you like to use this email address to manage multiple T-Mobile accounts?” I clicked YES and within a few more two-factor checks (text to my phone number) and verifying an answer to a security question I had on file -- I was able to get to my account! I was then able to set up a two-factor Authenticator app again (T-Mobile wants you to use Google Authenticator, but any app that can scan a QR code will work -- I am using the MS Authenticator app since all of my other accounts requiring two-factor are in there).
So, lesson learned from an Identity Access Management (IAM) stance -- T-Mobile doesn’t seem to understand that some people prefer to use only one email address and that their account binding process doesn’t work when someone leaves and then comes back. In the IAM world, this is the MLJ issue (MLJ stands for Move, Leave, Join). Since this user ID isn’t used anywhere else, it’s not a Federation issue… it’s just crappy IAM management.
Well, good luck to you guys! I am in and I was able to map to my NetFlix account and pick up the free year of Paramount+.
Cheers!
Scott a.k.a TheBeerGenius
You are the man Scott!
This was frustrating me for a while. I was finally on hold for technical support when I came across this post.
For anyone that is still having problem with this issue:
Get to the screen where you can select sign up. Sign up normally. Then select yes when asked if you want to use your XXX email to manage all of your TMobile accounts. Voila!
Exact same problem as of 7/12/2022. Almost the same case as those above -- returning customer from an experiment with a different carrier (trying to save a few bucks); well, their [the other carrier] service sucked and I am coming back to T-Mobile after about a 4 month break in service.
But, I have been on the phone with 611 for the past 30 minutes and I have even given them the link to this Community post -- it seems that they *STILL* don’t have a use case in their playbook for how to remedy this.
I will update this post if I ever get resolution.
Ok, so without any help from T-Mobile (611)… sorry to say, but they are nice, chipper, and well-meaning, but some are ill-equipped to handle this (and the word “expert” is thrown around too liberally). So, I finally got access to my account. I ultimately kept clicking on different ways to login (with a user ID, my phone, and of course my old email address that was linked).
Now, I apologize if this gets gray, but sadly I didn’t write down all of these steps that got me access, but here’s a rundown from what I can remember. Through trying to login different ways, e.g., forgot password, or using my phone number, or using an older username I found, I ultimately got to an error page that told me that “the email account you just used is already in use, would you like to use this email address to manage multiple T-Mobile accounts?” I clicked YES and within a few more two-factor checks (text to my phone number) and verifying an answer to a security question I had on file -- I was able to get to my account! I was then able to set up a two-factor Authenticator app again (T-Mobile wants you to use Google Authenticator, but any app that can scan a QR code will work -- I am using the MS Authenticator app since all of my other accounts requiring two-factor are in there).
So, lesson learned from an Identity Access Management (IAM) stance -- T-Mobile doesn’t seem to understand that some people prefer to use only one email address and that their account binding process doesn’t work when someone leaves and then comes back. In the IAM world, this is the MLJ issue (MLJ stands for Move, Leave, Join). Since this user ID isn’t used anywhere else, it’s not a Federation issue… it’s just crappy IAM management.
Well, good luck to you guys! I am in and I was able to map to my NetFlix account and pick up the free year of Paramount+.
Cheers!
Scott a.k.a TheBeerGenius
Exact same problem as of 7/12/2022. Almost the same case as those above -- returning customer from an experiment with a different carrier (trying to save a few bucks); well, their [the other carrier] service sucked and I am coming back to T-Mobile after about a 4 month break in service.
But, I have been on the phone with 611 for the past 30 minutes and I have even given them the link to this Community post -- it seems that they *STILL* don’t have a use case in their playbook for how to remedy this.
I will update this post if I ever get resolution.
Me too. This is maddening! I am sure it’s because I was a T-Mobile customer up until 2021 and I am returning. The old account record still has this mobile number attached and obviously they’d use the mobile phone as the primary key on the record, or at least a non-unique key in a cluster, so …
It doesn’t seem like T-Mobile has developed a thorough “Use Case” for a returning customer. Of if they did, they totally missed this part!
UGHHHHHHHHHHHHHH
(But they are still better than Verizon. The support team is very chipper. Good coffee?)
I am having the same issue right now. how did you guys solve this problem?
I'm having the same issue too. Can't sign up for my free Netflix because off it too
Same for me.
I'm having the same issue too. Can't sign up for my free Netflix because off it too
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