Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello, AdrianWatt
Based on your description, it seems that your Microsoft account (with the Internode address) has a Microsoft 365 Family subscription, and you want to share it with the Microsoft account (with the Hotmail address).
You can do this. For more information, please refer to: Share your Microsoft 365 Family subscription - Microsoft Support
You can access your Internode account using your phone number, but you cannot access your Internode account using the Hotmail address.
Generally, if you need to access your Microsoft account with a different email address or phone number, you can do so by adding an alias.
However, the Hotmail address has already been used by you to create a new Microsoft account, and it cannot be an alias for other Microsoft accounts.
For more information, see Add or remove an email alias in Outlook.com - Microsoft Support.
The phone number can be used.
Please note: The same phone number cannot be associated with two Microsoft accounts. To add it as an alias for another Microsoft account, you must first remove it from the original account.
Please let me know if my reply is helpful to you.
Best wishes,
Lucia Wu - MSFT | Microsoft Community Support Specialist