There are two different ways by which you can easily upgrade office. One is for the one-time purchase and other is for the Microsoft 365. If you have a Microsoft 365 installed than you don’t need to upgrade your office because you already have the most current version of Office and in near future, you will continue to receive the updates with no additional cost but if you are using a one-time purchase office you can upgrade that to any other product depending on the requirement and easily download the office setup from with the help of your product key.

Renew Office 365 Subscription
Visit in your browser.
2. Select the subscription you want to renew and then choose Renew now to pay now for a full year of Office 365 or Renew with a monthly subscription to pay for a month at a time.
Turn off recurring billing in Office
Go to the Services & subscriptions page by visiting
2. On the Services & subscriptions page, find your ms Office 365 subscription and then choose Manage.
3. Now click on Turn off recurring billing link to turn recurring billing off.
Change how you pay for a subscription

If you have a plan with recurring billing, you can change how you pay unless if you have a due payment. just follow the steps below.

Sign in to Services and subscriptions with your Microsoft account.
Select Manage, and then select Change how you pay.
Change how you pay gives you a list of your current payment options.
Add a new way to pay from that list and follow the instructions.

However, for a prepaid plan, you can’t change how you pay.