Cal. Bus. & Prof. Code § 5536.2
Each county or city which requires the issuance of any permit as a condition precedent to the construction, alteration, improvement, or repair of any building or structure shall also require as a condition precedent to the issuance of the permit a signed statement that the person who prepared or was in responsible control of the plans and specifications for the construction, alteration, improvement, or repair of the building or structure is licensed under this chapter to prepare the plans and specifications, or is otherwise licensed in this state to prepare the plans and specifications.
The signature and stamp, as provided for in Section 5536.1, on the plans and specifications by the person who prepared or was in responsible control of the plans and specifications shall constitute compliance with this section.
It is the responsibility of the agency that issues the permit to determine that the person who signed and stamped the plans and specifications or who submitted the signed statement required by this section is licensed under this chapter or is otherwise licensed in this state to prepare the plans and specifications.
This section shall not apply to the issuance of permits where the preparation of plans and specifications for the construction, alteration, improvement, or repair of a building or structure is exempt from this chapter, except that the person preparing the plans and specifications for others shall sign the plans and specifications as provided by Section 5536.1.
Ca. Bus. and Prof'l. Code § 5536.2