Cal. Civ. Code § 2937

(a) The Legislature hereby finds and declares that borrowers or subsequent obligors have the right to know when a person holding a promissory note, bond, or other instrument transfers servicing of the indebtedness secured by a mortgage or deed of trust on real property containing one to four residential units located in this state. The Legislature also finds that notification to the borrower or subsequent obligor of the transfer may protect the borrower or subsequent obligor from fraudulent business practices and may ensure timely payments.
It is the intent of the Legislature in enacting this section to mandate that a borrower or subsequent obligor be given written notice when a person transfers the servicing of the indebtedness on notes, bonds, or other instruments secured by a mortgage or deed of trust on real property containing one to four residential units and located in this state.
(b) Any person transferring the servicing of indebtedness as provided in subdivision (a) to a different servicing agent and any person assuming from another responsibility for servicing the instrument evidencing indebtedness, shall give written notice to the borrower or subsequent obligor before the borrower or subsequent obligor becomes obligated to make payments to a new servicing agent.
(c) In the event a notice of default has been recorded or a judicial foreclosure proceeding has been commenced, the person transferring the servicing of the indebtedness and the person assuming from another the duty of servicing the indebtedness shall give written notice to the trustee or attorney named in the notice of default or judicial foreclosure of the transfer. A notice of default, notice of sale, or judicial foreclosure shall not be invalidated solely because the servicing agent is changed during the foreclosure process.
(d) Any person transferring the servicing of indebtedness as provided in subdivision (a) to a different servicing agent shall provide to the new servicing agent all existing insurance policy information that the person is responsible for maintaining, including, but not limited to, flood and hazard insurance policy information.
(e) The notices required by subdivision (b) shall be sent by first-class mail, postage prepaid, to the borrower’s or subsequent obligor’s address designated for loan payment billings, or if escrow is pending, as provided in the escrow, and shall contain each of the following:
1. (1) The name and address of the person to which the transfer of the servicing of the indebtedness is made.
2. (2) The date the transfer was or will be completed.
3. (3) The address where all payments pursuant to the transfer are to be made.
(f) Any person assuming from another responsibility for servicing the instrument evidencing indebtedness shall include in the notice required by subdivision (b) a statement of the due date of the next payment.
(g) The borrower or subsequent obligor shall not be liable to the holder of the note, bond, or other instrument or to any servicing agent for payments made to the previous servicing agent or for late charges if these payments were made prior to the borrower or subsequent obligor receiving written notice of the transfer as provided by subdivision (e) and the payments were otherwise on time.
(h) For purposes of this section, the term servicing agent shall not include a trustee exercising a power of sale pursuant to a deed of trust.