How to Write an Affidavit for Child Custody in California

If you’re preparing for a child custody hearing in California, you’ll need to submit a written statement explaining why your proposed custody arrangement serves your child’s best interests. Here’s an important distinction: California family courts use “declarations” rather than traditional affidavits. Declarations carry the same legal weight but don’t require notarization, saving you time and money. Your declaration gives the judge your perspective and can significantly influence custody decisions. This guide covers California’s requirements and how to write an effective declaration.

Understanding Affidavits and Declarations in California Custody Cases

A declaration is a written statement made under penalty of perjury. Under California Code of Civil Procedure Section 2015.5, declarations have the same legal force as notarized affidavits, meaning you can face criminal charges for knowingly providing false information.

You’ll need a declaration when filing a Request for Order for custody (Form FL-300), requesting modifications to existing orders, or responding to the other parent’s filings. Use form MC-030 (Declaration), with MC-031 for additional pages.

The Difference Between Affidavits and Declarations

California family courts use declarations, which don’t require notarization and are the standard accepted format. Traditional affidavits requiring notaries are rare in custody cases and mainly used in contempt proceedings.

California Legal Requirements for Custody Declarations

The most important requirement is the penalty-of-perjury statement. If signing in California, end with: “I declare under penalty of perjury under the laws of the State of California that the foregoing is true and correct.” If signing outside California, include “under the laws of the State of California.”

Your declaration needs your signature, date, and place of execution (city and state). Courts limit declarations to 10 pages maximum, excluding exhibits. Type or write neatly in black or blue ink.

Essential Formatting Requirements

Include a proper caption with court name, case number, and parties’ names. Number each paragraph for easy reference. Use standard white paper with a clear title like “Declaration of [Your Name] in Support of Request for Custody.”

File at least 16 court days before the hearing if serving in person, or 21 days if serving by mail.

Step-by-Step Guide to Writing Your Custody Declaration

Step 1: Start With the Proper Introduction

Identify yourself and explain why you’re filing. State your relationship to the child and your personal knowledge of the facts.

Example: “I, Brian Johnson, am the father of Emily Johnson, born March 15, 2018. I am filing this declaration in support of my Request for Order for primary physical custody. I have personal knowledge of the facts stated herein.”

Step 2: Focus on the Child’s Best Interests

California law requires judges to prioritize the child’s health, safety, and welfare. Address your involvement in daily care, the child’s ties to school and community, home stability, and each parent’s ability to support the child’s relationship with the other parent.

Step 3: Include Specific Facts With Dates and Details

Avoid vague statements. Instead of “She never takes care of the kids,” write: “On January 15, February 20, and March 14, 2025, Respondent returned the children without having provided dinner, as evidenced by text messages (Exhibit 1).”

Show your involvement with concrete examples: “I attended all 12 of Emily’s pediatrician appointments in 2024 and coordinated her asthma medication schedule with her school nurse.” Document school attendance, consistent housing, and participation in activities.

Step 4: Attach Supporting Evidence and Conclude Properly

Support statements with documentation: school records, medical records, text messages, emails, or photos. Number exhibits sequentially and explain each one: “Exhibit 3 is an email from Emily’s teacher dated May 10, 2025, confirming my attendance at conferences.”

End with the required penalty-of-perjury statement, signature, date, and place of execution. Make copies before filing.

What to Include in Your Custody Declaration

Focus on facts you personally witnessed. Describe daily parenting: meals, homework help, bedtime routines, and transportation. Document involvement in school events, medical appointments, and extracurricular activities. Show stability through length of residence and community connections. Demonstrate co-parenting ability by providing examples of facilitating the other parent’s relationship with your child.

Critical Mistakes to Avoid

Don’t include hearsay. Write only what you witnessed. Instead of “My friend told me she drinks,” write “On July 4, 2025, at 9 a.m., I observed slurred speech and smelled alcohol during pickup.”

Avoid inflammatory language. Skip “terrible parent.” Use facts: “Respondent attended 2 of 12 soccer games between January and June 2025.”

Don’t make legal arguments. State facts, not conclusions. Describe behavior rather than citing statutes.

Avoid absolutes. Words like “always” and “never” undermine credibility.

Watch procedural errors. Use exact penalty-of-perjury language. Don’t exceed 10 pages. Meet service deadlines. Attach referenced exhibits. Number paragraphs. Use current forms from www.courts.ca.gov.

Moving Forward And Next Steps

Your declaration gives you a direct voice in court. Focus on specific facts and examples demonstrating your involvement and how your proposal serves your child’s best interests. Be honest and thorough.

Download forms from the California Courts website. Your local Family Law Facilitator can help with forms at no cost. For complex cases involving domestic violence, substance abuse, or if the other parent has an attorney, consider consulting a family law attorney.

This guide provides general information. Every case is unique, and an attorney can provide advice specific to your situation.

When to Consult a Child Custody Attorney

While many parents successfully file declarations themselves, certain situations benefit from professional legal guidance. Consider consulting an experienced Southern California child custody lawyer if your case involves domestic violence, substance abuse allegations, relocation disputes, or complex custody modifications. If the other parent has legal representation, you may be at a disadvantage without your own attorney. Family law attorneys can review your declaration, develop legal strategy, and represent you in court to protect your parental rights.