California Code, Unemployment Insurance Code - UIC § 1111

The director for good cause may extend for not to exceed 60 days the time for making a return or report or paying without penalty any amount required to be paid under this division. Any employer to whom an extension is granted and who pays the amount required within the period for which the extension is granted shall pay, in addition to the contributions, interest at the adjusted annual rate and by the method established pursuant to Section 19521 of the Revenue and Taxation Code from the date on which the payment would have been delinquent without the extension until the date of payment.