Can a child support order entered by default be changed in California?

What the law says

Family Code section 3692: “Notwithstanding any other provision of this article, or any other law, a support order may not be set aside simply because the court finds that it was inequitable when made, nor simply because subsequent circumstances caused the support ordered to become excessive or inadequate.”

Within a reasonable time, and no more than six months after the order, Code of Civil Procedure section 473(b) lets the court relieve a party from an order taken through “mistake, inadvertence, surprise, or excusable neglect,” with the proposed response attached. Once that six-month limit has run, Family Code section 3690(a) allows relief only on the grounds and within the time limits in section 3691, and section 3690(b) requires a finding that those grounds materially affected the original order and that the moving party would materially benefit.

Section 3691(c)(1) covers a default where service “has not resulted in notice to a party in time to defend the action for support.” The motion must be filed “within a reasonable time, but in no event later than six months after the party obtains or reasonably should have obtained notice” of the order or that their income and assets are subject to attachment, with a sworn statement and the proposed response. Under section 3691(c)(3), it cannot be granted if service followed the legal requirements. Fraud and perjury motions are due within six months after the fraud or perjury was discovered or reasonably should have been discovered. Section 3690(c) says these rules do not limit sections 17432 and 17433.

For a default in a local child support agency case, section 17432, in the version from Senate Bill 343 operative January 1, 2026, applies to support orders based on presumed income or earning capacity. The court may set aside the support amount if the parent’s income or earning capacity was “substantially different” from what was presumed, meaning a difference that would change the order by 10 percent or more (section 17432(c)). A party, including the agency, may file the motion “within two years of the local child support agency’s first collection of money through an earnings assignment order or an order or notice to withhold income for child support” (section 17432(g)(1)); the version in effect before 2026 allowed one year from the first collection. The agency must tell both parents in writing when that first collection comes in, and if the court grants relief, the new order has the same start date as the order set aside (section 17432(j)).

Modification is the other path: section 3651(a) lets a court modify a support order “at any time as the court determines to be necessary,” but under 3651(c)(1) not as to amounts that came due before the filing.

• Family Code section 3692 (leginfo.legislature.ca.gov)
• Code of Civil Procedure section 473 (leginfo.legislature.ca.gov)
• Family Code section 3690 (leginfo.legislature.ca.gov)
• Family Code section 3691 (leginfo.legislature.ca.gov)
• Family Code sections 17400 to 17432.5, both versions of each section (leginfo.legislature.ca.gov)
• Family Code section 3651 (leginfo.legislature.ca.gov)

What to do next

Because modification only runs from the filing date, consider filing a Request for Order (FL-300) with a current FL-150 now, even while you look into a set-aside. Rule 5.260(a) requires a current FL-150 for support hearings, though in some child support cases the simplified FL-155 can be used instead.

• FL-300, box by box
• FL-150, section by section
• Setting aside a default support or paternity judgment
• What is the new child support law for 2026 in California?