When changing an Azure B2C email adress, do I need to change the UPN as well

Question

In Azure B2C with the GraphAPI I can change the email address of an existing user with a http PATCH command: https://azure.microsoft.com/nl-nl/documentation/articles/active-directory-b2c-devquickstarts-graph-dotnet/

"SignInNames": [
{
  "type": "emailAddress",
  "value": "[email protected]"
}

This works, and I can login with the new email address.

But this leaves the UPN at the old value, do I need to set the UPN as well, or is there no harm in having the UPN stay at the old email address?

Answer 1

Yes, there is no need to update the UPN field.

Answer 2

Using v1.0 version of Microsoft Graph API, the body of the PATCH request to change the SignIn email address should be as following:

      {"identities":[{
        "signInType":"emailAddress",
        "issuer":"yourTenantName.onmicrosoft.com",
        "issuerAssignedId":"[email protected]"
      }]}