What is the maximum length of issuerAssignedId?

Question

What is the maximum length of issuerAssignedId?

The document https://learn.microsoft.com/en-us/graph/api/resources/objectidentity?view=graph-rest-1.0 says it issuer-assigned ID should be less than 64 characters. However, in our test environment, we confirmed that B2C allows email addresses exceeding 64 characters in either the local part or the full address, as long as the total length does not surpass 100 characters.

So we would like to understand more

Answer 1

Hello Shruthi Gowda,

Thank you for reaching out to Microsoft Support!

The maximum length of the issuerAssignedId in Microsoft Graph API is generally specified as 64 characters. However, there are some nuances based on the context in which it is used:

1. For email addresses: When the signInType is set to emailAddress, the issuerAssignedId must be a valid email address. In practice, this means that while the local part of the email address can exceed 64 characters, the total length of the email address should not surpass 100 characters. Please refer to documentation.
2. For user names: When the signInType is set to userName, the issuerAssignedId must begin with an alphabetical character or number and can only contain alphanumeric characters and certain symbols. The length constraint here is also 64 characters. Please refer to documentation.

It seems your test environment aligns with these practical constraints, allowing email addresses to exceed 64 characters in the local part or the full address, provided the total length does not exceed 100 characters.

Hope this helps.

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