Sts. & Hy. Code, § 8773

In order to facilitate the making of proportionate payments, the holders of outstanding bonds shall surrender them to the treasurer for registration and cancellation. Upon cancellation each holder shall be credited with the amount of his bond so canceled. Thereupon the treasurer shall by warrant pay to each holder the proportionate amount of principal and accrued interest due on his or her bonds as may be available from time to time out of the money in the redemption fund. Interest shall cease on payments made on account of principal from the date of payment, but interest shall continue to run on the unpaid principal at the rate specified in the bonds until payment thereof be made. No premiums shall be paid on payments made in advance of the due date. If bonds are not surrendered for registration and payment the treasurer shall give notice to the holder thereof by registered mail, at the holder’s address as last known to the treasurer, of the amount available for payment. Thereupon interest shall cease as to the amount so available for payment 10 days from the date of mailing of the notice.