Follow these steps in order. Stop when one step fixes it and report which step failed and any exact error message.
- quick check — can you sign in on the web?
Open an incognito/private browser window.
Go to https://portal.office.com and sign in with your business email.
- If you can sign in on the web, the problem is your laptop/Outlook app. Skip to step 8. If you cannot sign in, continue.
- try self-service password reset (SSPR)
Go to https://passwordreset.microsoftonline.com → “I forgot my password.”
Follow the prompts.
- If SSPR is disabled, you will be told. Continue to step 3.
- as admin reset password from another admin account or use support
If you have another global admin user, sign in at https://admin.microsoft.com → Users → Active users → select your user → Reset password.
- If you are the only admin and you cannot sign in, you must contact Microsoft support to recover the tenant (see step 12).
- check subscription and billing (tenant suspension)
Sign in to https://admin.microsoft.com → Billing → Your products or Subscriptions.
Confirm the subscription is active and payment succeeded.
- If billing failed the tenant or mailboxes may be suspended. Fix payment then retry sign-in.
- check user status and license (must have Exchange license)
Admin center → Users → Active users → find your account.
Confirm: account is not blocked, sign-in allowed, and an Exchange Online / Microsoft 365 license is assigned.
If license missing, assign it and wait a few minutes.
- check MFA and authentication settings
Admin center → Users → Multi-factor authentication (or Azure AD → Users → Authentication methods).
If MFA is blocking you, use the recovery phone/email or the authentication app.
- If you cannot pass MFA and there is no alternate method, reset via another global admin or support.
- view sign-in failure reason (diagnose cause)
Admin center → Azure Active Directory → Sign-ins (or follow link from admin center).
- Find your failed sign-in entry. Note the failure reason (invalid password, blocked, conditional access). Use that reason for next steps.
- if web sign-in works but Outlook/desktop fails (client fix)
Sign out of Office apps: Outlook → File → Office Account → Sign out.
Clear cached credentials: Control Panel → Credential Manager → Windows Credentials. Remove any Office/Exchange entries.
Create a new Outlook profile: Control Panel → Mail → Show Profiles → Add → set up account.
Or remove and re-add the account in Windows Mail/Outlook.
- If still failing, run Settings → Apps → Microsoft 365 → Modify → Online Repair.
- Windows 11 upgrade checks (device registration / conditional access)
Settings → Accounts → Access work or school. Ensure the device is Azure AD joined or registered if your tenant requires it.
- If Conditional Access policies require device compliance, you must re-enroll device into Intune or mark it compliant.
- mailbox existence and recovery (if email/data missing)
Admin center → Users → Deleted users. If your user was deleted, restore it.
Admin center → Exchange admin center → Recipients → Mailboxes. Confirm mailbox exists.
- If mailbox deleted, it may be restorable for a limited time. Follow restore steps in admin center.
- emergency options if you cannot fix access yourself
If you are locked out as the only global admin, use admin.microsoft.com → Support → New service request to open a Microsoft support case.
- Be ready to provide tenant name, domain, proof of purchase, billing info, and admin contact email. Microsoft may require identity verification.
- final checks and next steps summary
If sign-in failures show “invalid password”: reset password (steps 2–3).
If failures show “license missing” or “account blocked”: fix license or unblock the account in admin center.
- If failures show “conditional access” or “device not compliant”: rejoin/register device or change policy, or sign in from a compliant device.
If web sign-in works but Outlook still fails: clear credentials, make new profile, repair Office.Try these steps in order and let me know which one stops you, or paste the exact error message if it still fails.Please.