problem with my subscription

Sign in with the Microsoft account used for the purchase and install Microsoft 365 from Services & subscriptions; a separately supplied product key normally is not required.

Install Microsoft 365

1. Open Microsoft account Services & subscriptions.
2. Sign in with the same personal Microsoft account used when purchasing Microsoft 365.
3. Locate the active Microsoft 365 subscription.
4. Select Install, download the installer, and run it.
5. After installation, open Word or Excel and sign in with that same account to activate Microsoft 365.

Microsoft 365 subscriptions use the linked Microsoft account for installation and activation instead of a product key.^1^

If the subscription is not listed

Because your account is being billed, do not purchase Microsoft 365 again.

1. Open Microsoft account Order history and look for the Microsoft 365 charge.
2. If the charge is absent, sign out and check any other personal Microsoft accounts you may have used. The subscription may be attached to a different email address.
3. Search your email accounts for the Microsoft purchase confirmation; it can identify which account received the order.
4. If necessary, use Microsoft’s account-recovery guidance to identify the account associated with Microsoft 365.^2^

If the charge appears in Order history but Microsoft 365 still does not appear under Services & subscriptions, contact Microsoft Accounts and Billing Support:

1. Go to Microsoft Support.
2. Sign in.
3. Enter Chat with an agent.
4. Select Contact support, then follow the prompts for products, services, and billing.
5. Give the agent the order number, charge date, and the Microsoft account used for the purchase. Do not post those details publicly.

Accounts and Billing Support can investigate a paid order that is not attached to the visible subscription account.^3^

Retail purchase exception

If Microsoft 365 was purchased as an unused prepaid card from a retailer, the card should contain redemption instructions and a product key. If it was purchased directly from Microsoft as a digital subscription, use the account-based installation above rather than looking for a key.

References

1. Using product keys with Microsoft 365 | Microsoft Support
2. I forgot the account I use with Microsoft 365
3. My Microsoft 365 purchase is not in my subscriptions, and I have only the order number received from Microsoft - Microsoft Q&A