Login to your account at
office.com/setup and go to the ‘Admin’ section. From
here, you need to click on the ‘Billing’ option followed by ‘Product &
services’ page. From here, look for the subscription you wish to reactivate.
When the ‘Billing’ page opens, select ‘Reactivate’ and confirm your payment
details. In the end, you need to select ‘Reactivate’ once again.