In the Office 365 admin center, go to the Subscriptions page, or choose Billing > Subscriptions.
If you're using Office 365 Germany, go to this Subscriptions page.
If you're using Office 365 operated by 21Vianet, go to this Subscriptions page.
On the Subscriptions page, choose the subscription that you want to add licenses to and then choose Add/Remove licenses.
In the Total licenses box, enter the total number of licenses that you need for this subscription and then choose Submit > Close. For example, if you have 100 licenses and you need to add 5 more, enter 105.
If you pay for your subscription by credit card or bank account, any new licenses that you buy are available immediately after you receive an order confirmation. If you pay by invoice, you might have to wait for a credit check before your new licenses are available to use.
If you prepaid for your subscription with a product key, you can add more licenses by adding a credit card or bank account to cover the additional cost of the new licenses. After you have purchased the new licenses, we add a second subscription with the number of new licenses that you just added. For example, if you have a prepaid subscription with 5 licenses, and then bought 10 more licenses, you will see two subscriptions listed: one with the five prepaid licenses, and one with the 10 new licenses.
What if I don't see the Add/Remove licenses link?
This section describes the reasons why the Add/Remove licenses link might not be available, and what you can do about it.
If a credit check is pending, you’ll see a "Pending credit check" message, and you won’t be able to buy licenses until the credit check is completed. If a credit check is pending, check back later to see if the credit check has completed. Credit checks typically take up to two working days to complete.
After the credit check is complete, you should see the Add/Remove licenses link in the Users section. If so, go to Buy user licenses.
If the subscription was purchased and activated using a 25-character product key product key, you’ll see the text “Prepaid”. If your subscription was prepaid using a product key, see Add licenses to a subscription paid for using a product key.
If the subscription was purchased via a partner, you’ll see the Volume Licensing Service Center (VLSC) link. If your licenses were purchased via a partner see Add licenses to a subscription purchased through the Volume Licensing Service Center.
If the subscription was purchased via a Cloud Solution Provider (CSP) partner, you must contact your CSP partner to buy more licenses.
If you have a trial subscription, you must first buy your trial subscription, then you can add more licenses. A trial version of Office 365 will display the text “Trial”. For more information, see Buy a subscription to Office 365 for business from your free trial.
What you need to know about buying licenses for your Office 365 for business subscription
You need to be either a Global admin or a Billing admin. For more information, see About Office 365 admin roles.
To buy a license and add a new user to your subscription at the same time, see Add users individually or in bulk to Office 365 - Admin Help.
If you pay by credit card or bank account, the charge for buying new licenses will appear on your payment method in two days.
If you pay by invoice, the charge for buying new licenses will appear on your next billing statement.
If you buy new licenses in the middle of your billing period, your first billing statement might have a partial charge. The remaining amount will be included on your next billing statement.