Microsoft 365 Mobile Teams Login Drama
Posted by OriahVinree@reddit | sysadmin | View on Reddit | 19 comments
Any help is appreciated.
User is attempting to log into teams on their phone, being presented with the below error:
AADSTS50020 user account (their email) from identify provider https://sts.windows.net/(their tenant id) does not exist in tenant (their tenant name) and cannot access the application (teams id) (Microsoft Office) in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different ADD user account.
Have tried everything but fully formatting the phone, but this is their personal device and they would prefer not to.
Can sign into the same account on test phone, something is weird with this particular device. Have tried resetting everything I could possibly think of.
User is able to log into outlook, just not teams.
Thanks in advance
shortstuf888@reddit
Have you tried this? iOS tends to really hold onto O365 cached credentials and I've had to use this workaround for a tenant to tenant migration.
https://helpcenter.channelpartners.com/support/solutions/articles/38000017077-Sign-in-Issues-on-mobile-device-after-Tenant-to-Tenant-Migration-iOS-
Proto732@reddit
Spent 6 hours on this issue today before finding this post. Removing All Accounts via the edge://signin-internals fixed the MS Teams sign-in redirect issue. Question is … this user has been a part of our organization for a year with the same phone. Everything has been working for him without issue. He changed his domain password a few days back, (something he has done dozens of times since joining) and then suddenly his MS Teams login (only on iPhone) is getting redirected to an old tenant for a sister company, that he worked for years ago. Using the Remove All Accounts button required us to sign out of Edge with his user account. What are the chances that this could reoccur if he signs back into MS Edge with his corp identity, and his profile syncs to the iPhone again?
shortstuf888@reddit
I haven't seen the issue return after the Edge account clear. There's something with the way iOS caches accounts that makes it sticky and hard to remove old Microsoft accounts unless you uninstall all apps and MS Authenticator. Possibly a iCloud Keychain issue but I never really delved deep into the issue.
OriahVinree@reddit (OP)
Whoever you are, wherever you are, I want to give you a big fat sloppy kiss! This fixed the issue immediately. Thank you very much! I seriously appreciate it
shortstuf888@reddit
Glad to hear it worked for you!!!
zaphod777@reddit
Do they have a personal MS account with the same email address? IF so I would change the email on the personal account.
OriahVinree@reddit (OP)
This is an interesting thought, are you saying even if the domain is different this could be causing an issue?
The address is new, he's a new employee of my client so it's not been used to create any other account etc. it was created and licensed through m365
For example, the work address is john@businessdomain.com.au
If his personal ms is john@gmail.com, this could cause issues? I wouldn't have expected that
zaphod777@reddit
No, I was thinking if it was someone who registered a personal Microsoft account with the exact same domain and email address.
Although you might check and see if they had somehow set one up in between the time between you created the account and tried to sign in to their mobile device.
I've seem things get weird when that happens.
OriahVinree@reddit (OP)
Had a look into this and no, it's not possible for them to have done it, but it was a great thought
UDP53andSomtimesTCP@reddit
I believe zaphod777 is referring to a Microsoft Account (Live ID) with the same email address as the work / school account.
OriahVinree@reddit (OP)
Ah understood, thanks very much! It's very possible there is a tenant misconfiguration happening here, I'll dig deeper.
daxwire@reddit
The AADSTS50020 error on mobile specifically is a classic. Since Outlook works but Teams doesn't, it’s rarely a global tenant issue and usually a local 'broker' problem on the device.
Check if they have the 'Microsoft Authenticator' app installed. Even if they don't use it for 2FA, Teams often uses it as a broker for token management. If there's an old personal account or a 'stuck' registration in Authenticator, it’ll pass the wrong tenant ID to Teams every time.
Try clearing the 'Work or School' account from the iOS Settings > General > VPN & Device Management (or Accounts) too. Sometimes a stale profile there overrides the manual login.
If all else fails, check the Entra sign-in logs for that specific user. It’ll tell you exactly which 'identity provider' it thinks is sending the request—if it says 'Personal' while they're typing a work email, you've got a classic MSA/Work account collision.
Master-IT-All@reddit
I ran into this with an iPhone recently during a migration. I had to remove all connections to Exchange Online, cached connections in the mail app on the phone, contacts on the phone, basically all the apps that may have touched 365. And that included removing all the Microsoft apps.
Then once all the mail, contacts, calendar, and MS apps were all cleared down to nothing it requires installation in a specific order to get working.
MS Authenticator is the first, then add Outlook, Teams, OneDrive, and OneNote. If I ran into the error, I started again asking my Copilot for whatelse needs to be checked until I was able to get all apps connected.
UDP53andSomtimesTCP@reddit
Try this (you will need a spare iPhone that you can factory wipe)
Uninstall all Microsoft Work Apps
Backup and restore phone to another phone then factory reset original phone.
Backup and restore to original phone.
Reinstall from 2nd backup then re-install apps and sign in.
Note: Just making an iCloud backup and wiping / restoring to the same phone will keep those cached creds and issue will most likely persist.
OriahVinree@reddit (OP)
Great advice, thank you very much!
trebuchetdoomsday@reddit
assuming they're trying to sign in with their domain credentials and not as an external user, teams keeps thinking it's signing into a tenant other than your_domain.blah. a reinstall of teams usually fixes this.
OriahVinree@reddit (OP)
Yeah they are using their domain credentials, not as an external user. Reinstalled teams on their phone, didn't fix it.
DobleWho@reddit
They probably have some cached credentials from another tenant that it’s pulling first. Also check your CA policies and make sure they’re not on a VPN.
OriahVinree@reddit (OP)
I did my best re clearing cached credentials, this was my first thought. Do you have any specific recommendations on where to clear history/cache incase I missed somewhere?
CA policies are clear, no VPN being used.