California Civil Code
(a) (1)Except as otherwise provided by statute, where the original principal obligation is a loan for residential property of four units or less, the borrower under any note or evidence of indebtedness secured by a deed of trust or mortgage or any other lien on real property shall be entitled to prepay the whole or any part of the balance due, together with accrued interest, at any time.
(2) Nothing in this subdivision shall prevent a borrower from obligating himself, by an agreement in writing, to pay a prepayment charge.
(3) This subdivision does not apply during any calendar year to a bona fide loan secured by a deed of trust or mortgage given back during such calendar year to the seller by the purchaser on account of the purchase price if the seller does not take back four or more such deeds of trust or mortgages during such calendar year. Nothing in this subdivision shall be construed to prohibit a borrower from making a prepayment by an agreement in writing with the lender.
(b) Except as otherwise provided in Section 10242.6 of the Business and Professions Code, the principal and accrued interest on any loan secured by a mortgage or deed of trust on owner-occupied residential real property containing only four units or less may be prepaid in whole or in part at any time but only a prepayment made within five years of the date of execution of such mortgage or deed of trust may be subject to a
prepayment charge and then solely as herein set forth. An amount not exceeding 20 percent of the original principal amount may be prepaid in any 12-month period without penalty. A prepayment charge may be imposed on any amount prepaid in any 12-month period in excess of 20 percent of the original principal amount of the loan which charge shall not exceed an amount equal to the payment of six months’ advance interest on the amount prepaid in excess of 20 percent of the original principal amount.
(c) Notwithstanding subdivisions (a) and (b), there shall be no prepayment penalty charged to a borrower under a loan subject to this section if the residential structure securing the loan has been damaged to such an extent by a natural disaster for which a state of emergency is declared by the Governor, pursuant to Chapter 7 (commencing with Section 8550) of Division 1 of Title 2 of the Government Code, that the residential structure cannot be occupied
and the prepayment is causally related thereto.