this is what it says on website
As part of our commitment to security, you are required to answer a few verification questions during Step 3 of registration. These verification questions are based off of information from your TransUnion credit file.
If there’s not enough information in your TransUnion credit file to create questions, or if these questions are not answered successfully, Credit Karma asks for additional verification via identification documents.
If you are unable to complete Step 3 and have been asked to verify your identity via identification documents, you must mail or fax over photocopies of two different pieces of identification. We only need photocopies, not originals, and documents need to be valid (not expired).
You will need to include a letter indicating that you are sending documentation to verify your identity and activate your account.
Please choose 1 item from each of the following two lists:
Primary:
Driver’s License or State ID
Passport
Green Card /Temporary Resident Card
Birth Certificate
Secondary:
Another Primary Document
Social Security Card
Utility Bill. (Address must match at least one on file with TransUnion)
These photocopies can be sent to Credit Karma either by secure fax at 855-307-7212 or to our P.O. Box:
Credit Karma, Inc.
Attn: Member Support
P.O. Box 520
San Francisco, CA 94104-0520
For security reasons, please do not send your documentation by e-mail. Once we receive your documents, we’ll try to update your account within five business days. You will receive an automated email message once you have access to your account.