Rates for purchasing Web-based applications, electronic downloads, charges for use of licensed software, were earlier taxed at 15 percent service tax and these services now fall under the 18 percent GST (residual rate).To add your GST details to Office 365 subscription follow the steps:
To add GST number into any tenant, kindly refer to the following steps, by sign in as Global Admin to http://portal.office.com.
1. Go to the list of Billings/Subscriptions.
2. Expand the More Actions drop-down in any subscription and select Edit service usage address.
3. Enter your GST number in the provided field and click Save. Please click Additional Information to open your list of subscriptions.