Check the Validity and Availability of an Office 365 Tenant Name

Use letters and numbers only. Tenant name is case-insensitive.

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Advice When Selecting a New Tenant Name

You should thoroughly consider your new tenant name before you register it!

Although the tenant name doesn’t have to reflect your email domain or user login names, it will be visible in certain areas, like, e.g., SharePoint URLs.

Here are a few bullets to keep in mind:

  • Try to match your company brand as closely as possible.
  • Try to keep it short.
  • If you need to abbreviate a long name, check if the abbreviation conflicts with or denotes an existing 3rd party.
  • Consider your company’s long-term future; avoid geographical or other limiting denotations that may change.
  • Keep marketing and management in the loop before moving ahead with the registration.

You need a Microsoft Azure subscription in order to register a new tenant name.

If you already have a subscription, you can directly register a new tenant.

Tenant Name Checker Web API

(Fair use notice: You must include a link to if you use our free web service on your website)

You can also query the tenant name checker web API directly:[tenant name]

You can query the API with PowerShell using the following code (replace “contoso” with the tenant name):

$TenantName = "contoso"
$URI = "" + $TenantName
(Invoke-WebRequest -Uri $URI -Method GET -ContentType 'application/json').Content | ConvertFrom-Json

Sample output will look like this:

PS C:\> $TenantName = "contoso"
PS C:\> $URI = "" + $TenantName
PS C:\> (Invoke-WebRequest -Uri $URI -Method GET -ContentType 'application/json').Content | ConvertFrom-Json

name    status tenantId
----    ------ --------
contoso taken  31537af4-6d77-4bb9-a681-d2394888ea26

The resulting JSON will provide one of three different values in the ‘status’ field:

availableThe tenant name is available for registration.
takenThe tenant name is already registered.
invalidThe tenant name is invalid (must consist of only letters and numbers).