Cal. Government Code § 907

A local public entity, as defined in Section 900.4, may offset any delinquent amount due it for services rendered to any other local public entity. The offset may be charged, against any amount reciprocally owing, upon the giving of 30 days advance written notice, if no written dispute is received from the debtor within the 30-day notice period. Notices from the creditor or the debtor shall be made through certified mail. If the offset would result in the debtor’s inability to meet encumbered bonded indebtedness repayments, the debtor shall so state in a written dispute within the time period stated above. If a dispute notice is received and the dispute is subsequently resolved in favor of the entity to whom an amount is due, interest on the principal amount from the date that amount was originally owing shall be assessed at the legal rate per annum established pursuant to Section 685.010 of the Code of Civil Procedure. For purposes of this section, an amount reciprocally owing includes any tax revenue collected by a local public entity for disbursement to another local public entity.