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Customer Service Number (CSN)

The Customer Service Number (CSN) is used to access your ReadyReturn online. You only need a CSN if you are eligible and have a ReadyReturn ready.

We issue a new CSN each calendar year. The number is only valid during the year for which it is issued.

You will need the following to get your CSN:

  • Your social security number.
  • A copy of your original 2012 California tax return.
  • The California Adjusted Gross Income (AGI) from your 2012 tax return. (Use the chart below to find the line numbers.)
Form Number Line Numbers
Form 540 2EZ Line 16
Form 540 Line 17
Form 540NR (Long) Line 32
Form 540NR (Short) Line 32