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Customer Service Number (CSN)

Frequently Asked Questions

  1. What is a CSN?
  2. Who needs a CSN?
  3. Do I need a CSN to access MyFTB Account?
  4. How do I get my CSN?
  5. I can’t get my CSN. I received a message that my social security number and name do not match. What do I do?
  6. What if I lose my CSN?
  7. What happens if I use the wrong CSN?
  8. Can I use the same CSN next year?
  9. Can I change my CSN?
  10. What do you do with the information I enter while looking up my CSN?
  11. Can I get my CSN online?

  1. What is a CSN?

    A CSN is a 4-digit authentication number the Franchise Tax Board issues each taxpayer every year. The combination of the CSN and the taxpayer's social security number ensures confidentiality and security when accessing personal tax information online.

  2. Who needs a CSN?

    Taxpayers who qualify for the ReadyReturn program and want to access their current year return online need a CSN.

  3. Do I need a CSN to access MyFTB Account?

    No. A new secure method to login and view MyFTB Account information has replaced the CSN login method. Taxpayers and tax professionals must complete a one-time registration process to create a login account.

  4. How do I get my CSN?

    We offer two ways for you to get your CSN:

    1. You can look it up online.
    2. You can call us during business hours for assistance.
      CSN assistance only

      800.353.9032
      916.845.6600 (outside the U.S.)

      TTY/TDD
      800.822.6268 (for persons with hearing or speech impairments)

  5. I can’t get my CSN. I received a message that my social security number and name do not match. What do I do?

    Call during business hours for assistance.

    CSN assistance only

    800.353.9032
    916.845.6600 (outside the U.S.)

    TTY/TDD
    800.822.6268 (for persons with hearing or speech impairments)

  6. What if I lose my CSN?

    You can look up your CSN on our website any time, or call during business hours for assistance.

    CSN assistance only

    800.353.9032
    916.845.6600 (outside the U.S.)

    TTY/TDD
    800.822.6268 (for persons with hearing or speech impairments)

  7. What happens if I use the wrong CSN?

    You will not be able to access your ReadyReturn on our website if you use the wrong CSN. You must use the CSN that we issued to you.

  8. Can I use the same CSN next year?

    No. We issue each taxpayer a new CSN every year. The CSN you use in 2014 will not be valid in 2015.

  9. Can I change my CSN?

    Generally no. However, if you have a circumstance that requires a new CSN be issued, call during business hours:

    CSN assistance only

    800.353.9032
    916.845.6600 (outside the U.S.)

    TTY/TDD
    800.822.6268 (for persons with hearing or speech impairments)

  10. What do you do with the information I enter while looking up my CSN?

    We use the information only to verify your identity and retrieve the correct CSN.

  11. Can I get my CSN online?

    Generally, yes. You can check our list to see if you are using a compatible browser and operating system. We recommend that you log out and close your browser when you are done to ensure the highest level of security.