CA Fam Code Section 5700.506

(a)

An obligor may contest the validity or enforcement of an income-withholding order issued in another state and received directly by an employer in this state by registering the order in a tribunal of this state and filing a contest to that order as provided in Chapter 6, or otherwise contesting the order in the same manner as if the order had been issued by a tribunal of this state.

(b)

The obligor shall give notice of the contest to:

(1)

a support enforcement agency providing services to the obligee;

(2)

each employer that has directly received an income-withholding order relating to the obligor; and

(3)

the person designated to receive payments in the income-withholding order or, if no person is designated, to the obligee.