Acceptable ID
A notary always has to "properly" identify a signer before they can notarize a signer's document. In California, the Secretary of State publishes a very specific list of allowable forms of identification.
The ID's listed below must have been issued within the past 5 years and contain a photograph, a physical description, a signature, and a serial or identification #:
California Driver's License
California Identification Card
Out of State Driver's License
Out of State Identification Card
Canadian Driver's License
Mexican Driver's License
U.S. Military ID Card
U.S. Passport
Foreign Passport from the applicant’s country of citizenship
Employee ID issued by an agency or office of the state of California or a California city or county
Inmate ID Card (issued by the CA Dept. of Corrections, if inmate is in prison)
Inmate ID Card (issued by a sheriff's department, if the inmate is in a local detention facility)
Identification card issued by a federally-recognized tribal government
Oath/affirmation of one credible witness personally known to the Notary and identified through acceptable ID
Oath/affirmation of two credible witnesses not personally known to the Notary and identified through acceptable ID