Problem with adding phone number to MS Teams

[Adam1]

Hello!

I've downloaded MS Teams application to my computer. It asks me to add mobile phone number. When I receive code I put it into the field it says that this mobile phone number is already in use and I have to use another one (I don't have any other mobile phone number). I contacted your support and we tried to log in through the website also but there I have an information "Someone has already configured Teams application for you organization". And also it says I should use another email.

[#2]

@Adam1 See these for guidance.

Troubleshoot signing in or up - Office Support (microsoft.com) 

Someone has already set up Teams for your organization error in Microsoft Teams - Microsoft Teams | ...

[#3]

@ChristianBergstrom 

So I cannot use the same phone number for my personal account and work account?

Regarding error that my account is already set up none of these steps worked for me.

[#4]

@Adam1 I suggest you follow the instructions provided in the first link to, for ex., create an alias and remove the phone number from the primary account. I would also use InPrivate windows doing that.

Regarding the "Someone..." this can be one of a couple of things, such as a user has signed up for self-service subscription using your domain name etc. Difficult to say with the information provided.