Cal. Fam. Code § 5700.602

(a) Except as otherwise provided in Section 5700.706, a support order or income-withholding order of another state or a foreign support order may be registered in this state by sending the following records to the appropriate tribunal in this state:
1. (1) a letter of transmittal to the tribunal requesting registration and enforcement;
2. (2) two copies, including one certified copy, of the order to be registered, including any modification of the order;
3. (3) a sworn statement by the person requesting registration or a certified statement by the custodian of the records showing the amount of any arrearage;
4. (4) the name of the obligor and, if known:
  1. (A) the obligor’s address and social security number;
  2. (B) the name and address of the obligor’s employer and any other source of income of the obligor; and
  3. (C) a description and the location of property of the obligor in this state not exempt from execution; and
5. (5) except as otherwise provided in Section 5700.312, the name and address of the obligee and, if applicable, the person to whom support payments are to be remitted.
(b) On receipt of a request for registration, the registering tribunal shall cause the order to be filed as an order of a tribunal of another state or a foreign support order, together with one copy of the documents and information, regardless of their form.
(c) A petition or comparable pleading seeking a remedy that must be affirmatively sought under other law of this state may be filed at the same time as the request for registration or later. The pleading must specify the grounds for the remedy sought.
(d) If two or more orders are in effect, the person requesting registration shall:
1. (1) furnish to the tribunal a copy of every support order asserted to be in effect in addition to the documents specified in this section;
2. (2) specify the order alleged to be the controlling order, if any; and
3. (3) specify the amount of consolidated arrears, if any.
(e) A request for a determination of which is the controlling order may be filed separately or with a request for registration and enforcement or for registration and modification. The person requesting registration shall give notice of the request to each party whose rights may be affected by the determination.