Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi,
If you recently renewed or purchased Microsoft 365 and now want to upgrade to Microsoft 365 Premium, you can upgrade using the same Microsoft account. Microsoft says that when switching to a subscription with more features, the remaining time on your current subscription is automatically converted and added to the new Premium subscription.
Sign in to https://account.microsoft.com/services using the same Microsoft account, find your current Microsoft 365 subscription, and select Manage. Look for the option to switch or upgrade to Microsoft 365 Premium, then review the price and any adjustment for your remaining subscription time before confirming the purchase.
You may be charged for the Premium upgrade at the time of purchase, but the remaining time on your current subscription will be converted into additional time on your new Premium subscription.
If it doesn’t work or you need further assistance, for your security and privacy, I recommend contacting Microsoft Billing Support directly, as this request involves personal or sensitive information that should not be shared in a public forum.
Click this link: https://support.microsoft.com/contactus/
Sign in to your Microsoft account.
Select Microsoft 365 > Click 'Get home support'.
Type "Chat with an agent" from the text field and press Enter.
Click "Contact support" at the bottom.
Select the product you need help with.
Follow the prompts to connect with a live agent or request a call back.