My LLC's taxes are due soon and I want to pay the $800 annual tax here in California. I'm a little confused about something I'm supposed to write on the check: the "Calfirnia SOS file number". Google was no help; it returned results that are the FTB 3522 form, other forms, and non-CA SOS posts about John Kerry...

What does the California SOS file number mean and where can I find it?

Here are the full instructions:

Where to File

Using black or blue ink, make a check or money order payable to the "Franchise Tax Board." Write the California SOS file number, FEIN, and "2013 FTB 3522" on the check or money order. Detach the payment voucher from the...

  • whats a california of state file number and where to find it?
    – user16296
    Commented May 31, 2014 at 19:18
  • @user16296 You can find it at the site linked in the answer or in the location specified in the answer. :)
    – Danny
    Commented Jun 5, 2014 at 2:16

2 Answers 2


SOS is Secretary of State. SOS number is the number the Secretary of State office assigned to your entity.

You can find it on the LLC application form that you submitted (assuming you kept the copy of your application returned to you), or by searching for your entity on the SOS site here (the first column, "entity number", is what you're looking for).

  • 1
    Excellent, thank you! For future researchers: the "LLC application form" that @littleadv mentions is the document titled Articles of Organization of a Limited Liability Company (LLC).
    – Danny
    Commented Dec 3, 2013 at 7:09
  • The 100S form requires both a "california corporation number", and an "secretary of state file number". - I'd assumed the corporation number was the entity number, but could it be both?
    – Kevin
    Commented Mar 14, 2014 at 22:02
  • 1
    After further research, according to the 100s instructions, the SOS file number is 12 digits, not 7, as the Sos search returns. Not sure what/how you get such a number, but they seem to be able to "figure it out" if you give them the 7 digit entity number instead.
    – Kevin
    Commented Mar 14, 2014 at 22:14
  • @Kevin SOS assigns numbers to corporations in addition to the file number.
    – littleadv
    Commented May 31, 2014 at 19:47

The 7 digit corporation number can be found through a business entity search on the CA SOS website (specifically, http://businesssearch.sos.ca.gov/)

If you have a 7-digit corporation number, then you do not have a 12-digit file number. (A call to the Secretary of State's office revealed that they provide either a 7 digit corporation number or a 12 digit file number - not both.)

  • How do you use that 7-digit number to enroll for a CA EDD employer number then? It says invalid SoS number for me... Commented Apr 15 at 16:45

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