Enter your product key for a Microsoft business product or service

Check out all of our small business content on Small business help & learning.

A product key is a 25-character alphanumeric code that represents a prepaid license for a Microsoft business product or service. If you bought a Microsoft business product or service from a partner or a retail store, you use the product key to activate your new subscription. If you buy a prepaid license for a product that you already own, you can use the product key to extend the expiration date of your subscription. You can also use a product key to add more licenses to your subscription.

Need something else? - For help with Microsoft 365 Family or Microsoft 365 Personal, see Using product keys with Microsoft 365.
- Volume licensing customer? If you bought a Microsoft business product or service through a Microsoft Open License Program, see the article, Enter your product key purchased from Microsoft Open.

Before you begin

If you’re an existing customer, you must be a global or billing admin to do the tasks in this article. For more information, see About admin roles.

Activate a new subscription

  1. Go to https://microsoft365.com/setupbusiness.

  2. Enter your product key, then select Next.

  3. Enter your name, work email address, business phone number, company name, and country/region, then select Next.

  4. Enter a phone number to receive either a text or call to verify your identity.

  5. You can get a new domain, use a domain name you already own, or add a domain later. The steps can vary, so follow the prompts, depending on which option you choose.


    If you want to make sure that your subscription is automatically extended at the end of its term, you can add a credit card or bank account, and then change the recurring billing setting for that subscription.

  6. When you're finished, go to the Admin center to manage your subscription.

Extend the expiration date for an existing subscription

To extend the expiration date for your prepaid subscription, you must use a new, unused product key for the same Microsoft plan. Entering your original product key won't work because a key that has already been redeemed can't be used again.

  1. Go to the Microsoft 365 admin center.

    • If you’re using the Simplified view, select Billing.
    • If you’re using the Dashboard view, go to the Billing > Your products page.
  2. Select the subscription that you want to extend.

  3. On the subscription details page, in the Subscription and payment settings section, select Extend end date.

  4. On the renew or add user licenses page, select Use a new and unused product key, then select Next.

  5. Enter the product key, then select Next.


    If you have more than one product key, you can select Add another product key to enter them.

  6. Review your order details, then select Redeem.

Next steps

If you're new to Microsoft 365 for business, learn how to set up Microsoft 365.

Check out this list of common product key errors and solutions: Problems with your Microsoft 365 for business product key?

Or, call Microsoft Support.

Upgrade or change to a different Microsoft 365 for business plan (article)
What happens to my data and access when my Microsoft 365 for business subscription ends? (article)
Understand subscriptions and licenses in Microsoft 365 for business (article)