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 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 C. If your number starts with 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 4 may be electronically 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 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 business.e-file.coordinator@ftb.ca.gov.