California
Does child support go up automatically in California or do I have to ask?
Quick answer
You have to ask. A California child support order changes when a court modifies it, and under Family Code section 3651(c) the change cannot reach amounts that came due before the request was filed, so each month you wait is a month at the old amount. Either parent can ask with a Request for Order and a current Income and Expense Declaration.
Researched by Dan Martin, Legal Researcher · Published by Onbello Legal · Last updated October 2026
What the law says
Family Code section 3651(a): “Except as provided in subdivisions (c) and (d) and subject to Article 3 (commencing with Section 3680) and Sections 3552, 3587, and 4004, a support order may be modified or terminated at any time as the court determines to be necessary.”
Section 3651(c)(1) says a support order “may not be modified or terminated as to an amount that accrued before the date of the filing of the notice of motion or order to show cause to modify or terminate.” Section 3653(a) says the new order may be made retroactive to the filing date “or to any subsequent date,” so the filing date is the earliest a change can start. Section 3651(e) says all of this applies whether or not the order was based on an agreement.
California Rules of Court, rule 5.260(a) requires both parents to file and serve a current Income and Expense Declaration (FL-150) for any support hearing, and current means completed within the past three months with no facts changed. In child support hearings, a parent who qualifies may use the simplified Financial Statement (FL-155) instead.
What to do next
Run the numbers first with current incomes and parenting time. If you decide to ask, file a Request for Order (FL-300) with your FL-150, and serve it at least 16 court days before the hearing under Code of Civil Procedure section 1005(b), plus five calendar days if mailed within California.
Last checked against the sources above on October 6, 2026.
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Forms, deadlines, and local rules change. Verify anything on this page against the official self-help resources for your state before you rely on it.
This page is general legal information, not legal advice, and does not create an attorney–client relationship. Laws and local rules vary and change. For advice about your situation, consult a licensed family-law attorney in your state.
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