California has three identifying numbers for business returns:
Visit the California Secretary of State website to determine your entity's California ID number and type.
California Corporation Number starting with a "4:" In March of 2017, the California Secretary of State began issuing California Corporation Numbers that begin with a "4." The California electronic filing schema doesn’t allow for returns for 2014, 2015, or 2016 to be e-filed if the California Corporation Number begins with anything other than the letter "C." If your number starts with a "4," and you need to file a return for any of those years, it must be paper filed.
Returns with a California Corporation Number beginning with a "4" may be e-filed for 2017 and years after.
If the California Franchise Tax Board states requires that you e-file but you have a number that begins with a "4," you need to file a Business entity e-file waiver request and indicate you cannot file electronically due to technology constraints. For additional questions, contact your account manager or an e-file coordinator at: email@example.com.
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.