California Code, Family Code - FAM § 5600

(a) A local child support agency or obligee may register an order for support or earnings withholding, or both, obtained in another county of the state.

(b) An obligee may register a support order in the court of another county of this state in the manner, with the effect, and for the purposes provided in this part.  The orders may be registered in any county in which the obligor, the obligee, or the child who is the subject of the order resides, or in any county in which the obligor has income, assets, or any other property.