CA Fam Code Section 5700.603

(a)

A support order or income-withholding order issued in another state or a foreign support order is registered when the order is filed in the registering tribunal of this state.

(b)

A registered support order issued in another state or a foreign country is enforceable in the same manner and is subject to the same procedures as an order issued by a tribunal of this state.

(c)

Except as otherwise provided in this part, a tribunal of this state shall recognize and enforce, but may not modify, a registered support order if the issuing tribunal had jurisdiction.