onPremisesExtensionAttributes resource type

Namespace: microsoft.graph

The return type of the onPremisesExtensionAttributes property of the user object and extensionAttributes property of the device object. Returns 15 custom extension attribute properties. Each attribute can store up to 1024 characters.

On the user entity and for an onPremisesSyncEnabled user, the source of authority for this set of properties is the on-premises Active Directory that is synchronized to Microsoft Entra ID, and is read-only. For a cloud-only user (where onPremisesSyncEnabled is false or null), these properties can be set during creation or update. If a cloud-only user was previously synced from on-premises Active Directory, these properties can't be managed via the Microsoft Graph API. Instead, they can be managed through the Exchange Admin Center or the Exchange Online V2 module in PowerShell.

The extensionAttributes property of the device entity is managed only in Microsoft Entra ID during device creation or update.

Note: These extension attributes are also known as Exchange custom attributes 1-15.

Properties

Property	Type	Description
extensionAttribute1	String	First customizable extension attribute.
extensionAttribute2	String	Second customizable extension attribute.
extensionAttribute3	String	Third customizable extension attribute.
extensionAttribute4	String	Fourth customizable extension attribute.
extensionAttribute5	String	Fifth customizable extension attribute.
extensionAttribute6	String	Sixth customizable extension attribute.
extensionAttribute7	String	Seventh customizable extension attribute.
extensionAttribute8	String	Eighth customizable extension attribute.
extensionAttribute9	String	Ninth customizable extension attribute.
extensionAttribute10	String	Tenth customizable extension attribute.
extensionAttribute11	String	Eleventh customizable extension attribute.
extensionAttribute12	String	Twelfth customizable extension attribute.
extensionAttribute13	String	Thirteenth customizable extension attribute.
extensionAttribute14	String	Fourteenth customizable extension attribute.
extensionAttribute15	String	Fifteenth customizable extension attribute.

JSON representation

The following JSON representation shows the resource type.

JSON

{
      "extensionAttribute1": "string",
      "extensionAttribute2": "string",
      "extensionAttribute3": "string",
      "extensionAttribute4": "string",
      "extensionAttribute5": "string",
      "extensionAttribute6": "string",
      "extensionAttribute7": "string",
      "extensionAttribute8": "string",
      "extensionAttribute9": "string",
      "extensionAttribute10": "string",
      "extensionAttribute11": "string",
      "extensionAttribute12": "string",
      "extensionAttribute13": "string",
      "extensionAttribute14": "string",
      "extensionAttribute15": "string"
  }