CA Civ Code Section 8506

(a)

A stop payment notice to an owner shall be given to the owner or to the owner’s architect, if any.

(b)

A stop payment notice to a construction lender holding construction funds shall not be effective unless given to the manager or other responsible officer or person at the office or branch of the lender administering or holding the construction funds.

(c)

A stop payment notice shall comply with the requirements of Chapter 2 (commencing with Section 8100) of Title 1.