upgrade microsoft 365 license

You should be able to use the Microsoft 365 admin center where you hold billing permissions. Microsoft separates its subscriptions into Business and Enterprise families, so you cannot always use the automated "Upgrade" tab for a direct, one-click switch between these distinct categories. Instead, you need to manually purchase the new E1 or E3 licenses first, assign them to your existing users to ensure zero data loss, and then cancel or reduce the quantity of your old Business Basic licenses.

Your first step is to log into the Microsoft 365 admin center using your global admin or billing admin credentials. Once logged in, navigate through the left-hand menu to Billing, and then click on Purchase services or Marketplace. From this page, look up the exact enterprise license you need, select it, choose your billing frequency, and complete the purchase for the number of seats you require. Because you already have an E3 and E1 infrastructure established in your organization, these newly purchased seats will immediately appear in your available pool of licenses.

Next, you must transition your users to the new tier by navigating to Users, then clicking on Active users in the admin center. Click on the display name of a user currently on Business Basic, open the Licenses and apps tab in the flyout pane on the right, check the box next to your new E1 or E3 license, uncheck the box for Business Basic, and click Save changes. Alternatively, if you have dozens of users to move, you can select multiple users at once from the Active Users list, click the three dots for more options, choose Change licenses, and swap out the Business Basic license for the Enterprise tier across the entire batch simultaneously.

Once every user has been successfully moved to their new license, you must stop paying for the old, unused seats so you do not incur double billing. Go back to the left menu, select Billing, and click on Your products to view a full catalog of your active subscriptions. Click on your original Microsoft 365 Business Basic subscription, select Reduce license quantity to delete the now-empty seats, or click Cancel subscription if absolutely no users remain on that specific plan. If you bought your licenses through a Microsoft Cloud Solution Provider partner rather than directly from Microsoft, you will need to contact that specific vendor's portal to adjust these seat counts.

If you hit a roadblock during this process, you can bypass waiting for your pending email ticket by launching a direct support session from inside your admin panel. Click the Help & support headset icon in the bottom right corner of the admin center screen, type a brief phrase like "License upgrade assistance" into the search bar, and look for the contact support buttons at the bottom of the results window. Change the contact method from email to Phone or Live Chat, provide your current phone number, and a Microsoft commercial billing agent will typically call you back within a few minutes to complete the transaction on your behalf.

If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

hth

Marcin