Microsoft 365 · Entra ID
Microsoft 365 tenant ID lookup
Type a domain or an email address and see the Microsoft 365 tenant behind it: its tenant ID, where its directory is kept, the onmicrosoft.com name it was created with, and how the domain’s mail and Microsoft 365 records are set up. Several domains at once give a table.
- Public answers only, no sign-in
- Free, no account
- Up to 50 domains at once
What the answers mean
- Where do these answers come from?
- From Microsoft’s public sign-in configuration for the domain (login.microsoftonline.com/<domain>/v2.0/.well-known/openid-configuration) and from the domain’s DNS records. Anyone can ask both, without signing in.
- Is a tenant ID secret?
- No. It identifies a tenant, every Microsoft sign-in page and token shows it, and on its own it gives no access to anything.
- What is the initial domain?
- The onmicrosoft.com name a tenant gets when it is created, which it keeps for good. It shows here only where the domain uses Microsoft 365’s DKIM, whose records point to it.
- Why does a Swiss tenant show Europe?
- The region is where Microsoft keeps the tenant’s Entra ID directory, and Switzerland belongs to Europe there. Where mailboxes and files are stored is a separate matter, shown in the Microsoft 365 admin center.
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