Accessing Microsoft Teams Free using personal or organizational credentials
Hello SGreen3,
Greetings. Based on my test, I did not need to enter a phone number when signing up Teams free, I only need to enter the verification code that send to the email address which is used to sign up the free version of Teams.
Given this result, we recommend you may refer to the steps in below document to try again: Sign up for Teams free.
If the problem persists, please try to register a new Outlook.com account and try using this account to sign up Teams free to check the result.
Best regards,
Jennifer