Filing for divorce, legal separation, or nullity in California starts with one document: Form FL-100, Petition, Marriage/Domestic Partnership. Every other form in your case builds on what you write here, so getting it right the first time matters.
Key Takeaway: FL-100 is the form that opens your case. It identifies the parties, states your legal grounds, and tells the court what you're asking for. It is filed together with a Summons (FL-110) and, if you have minor children, a UCCJEA declaration (FL-105 or GC-120).
Form FL-100 is the California Judicial Council form titled "Petition, Marriage/Domestic Partnership." It is the document that legally opens a family law case for:
- Dissolution of marriage or domestic partnership (divorce)
- Legal separation
- Nullity (annulment)
You check one box near the top of the form to tell the court which of these three outcomes you're requesting. Everything that follows, the case number, hearings, disclosures, and eventual judgment, flows from this single filing.
FL-100 is filed with the Superior Court in the California county where you or your spouse meet the residency requirements: at least 6 months in the state and 3 months in the county. Legal separation does not require meeting this residency test, since it does not end the marriage.
The spouse or domestic partner who starts the case by filing FL-100 is called the Petitioner. The other spouse becomes the Respondent once they are served.
Filing first doesn't give you an advantage in how property, custody, or support are ultimately decided. It simply means you're the one who opens the case and sets the initial requests in motion. If you're weighing whether to file yourself or wait, our guide on How to File for Divorce in California Without a Lawyer walks through the decision and the full self-represented process.
<h2 id="companion-forms">Forms Filed Alongside FL-100</h2>FL-100 rarely goes to the courthouse alone. Depending on your situation, you'll typically file it together with:
| Form | Purpose | When It's Required |
|---|---|---|
| FL-100 | Opens the case; states grounds and requests | Always |
| FL-110 (Summons) | Officially notifies the Respondent and puts standard restraining orders (ATROs) in place | Always |
| FL-105 / GC-120 (UCCJEA) | Declares each child's residence history for custody jurisdiction | Only if there are minor children |
| FW-001 (Fee Waiver) | Requests a waiver of the filing fee based on income | Only if you can't afford the fee |
The Summons is worth understanding even though it's a separate form: from the moment it's served, both spouses are automatically bound by Automatic Temporary Restraining Orders (ATROs) that limit things like moving children out of state, cashing out insurance policies, or transferring property outside the normal course of business.
<h2 id="section-by-section">Section-by-Section Walkthrough of FL-100</h2>Here's what you'll actually fill in, section by section.
1. Case Information and Parties
At the top, you'll enter the county, the names of the Petitioner and Respondent, and, once assigned, the case number. Use full legal names exactly as they appear on your marriage or partnership certificate.
2. Statistical Facts
This section asks for the date of marriage or domestic partnership, the date of separation, and the resulting length of the marriage. The separation date matters because California is a community property state: it generally marks the point where property and debts stop being shared and start being separate.
3. Residency
You'll confirm that you or your spouse meet California's residency requirements (6 months in the state, 3 months in the filing county) if you're requesting dissolution. Legal separation petitions can skip this requirement entirely.
4. Legal Grounds
California is a no-fault divorce state. The standard box to check is irreconcilable differences, meaning the marriage has broken down and can't be repaired. You don't need to prove anyone did anything wrong, and the form doesn't ask you to.
5. Minor Children
If you and your spouse have minor children together, you'll list their names, birthdates, and where they currently live. This triggers the requirement to also file the UCCJEA declaration (FL-105 or GC-120) so the court can confirm it has jurisdiction over custody.
Only list children of this marriage or partnership. Children from other relationships aren't part of this case, even if they live in the same household.
6. Property
FL-100 asks you to identify, at a general level, what property and debts exist and whether they're separate or community:
- Separate property, generally anything owned before the marriage, or received individually by gift or inheritance during the marriage
- Community property, generally anything earned or acquired by either spouse during the marriage
You aren't listing every asset here (that level of detail comes later, in your financial disclosures). FL-100 just flags that property exists and needs to be divided.
7. Spousal Support
You'll check a box indicating whether you're requesting spousal support, reserving the right to request it later, or asking that no support be ordered. This doesn't set an amount, it simply preserves your options.
8. Requests for Relief
The final section is where you check boxes for everything you're asking the court to grant: dissolution or legal separation status, property division, spousal support, attorney's fees, and, if applicable, child custody and child support. Be thorough here. In a default case, the judgment generally can't grant more than what you requested in this section.
- Leaving the "requests for relief" boxes incomplete, which can limit what the court can later award, especially in a default
- Listing an inaccurate date of separation, which affects how property and debts are divided
- Forgetting to check a box for legal grounds
- Omitting minor children, or filing without the required UCCJEA declaration
- Using nicknames instead of full legal names for either party
- Filing in a county before confirming residency requirements are actually met
Filing FL-100 with the court clerk is only the first step. After filing:
- You must serve the Respondent with copies of the filed Petition and Summons, generally through someone over 18 who is not a party to the case
- The Respondent has 30 days from service to file a Response (FL-120)
- California's mandatory 6-month waiting period begins on the date of service, not the date you filed
- Both spouses must complete financial disclosures before the case can move to judgment
That 6-month clock is one of the most misunderstood parts of the process. Filing early doesn't shorten it, and it can't be waived even if both spouses agree on every issue. For a full breakdown of what affects your timeline, see How Long Does Divorce Take in California?
<h2 id="filing-fee">Filing Fee and Fee Waiver</h2>Filing FL-100 requires paying the Superior Court's filing fee, which generally runs $435 to $450 depending on the county. This fee is separate from any cost of preparing the paperwork itself.
If you can't afford the filing fee, you can request that it be waived or deferred by filing Form FW-001 (Request to Waive Court Fees) along with your Petition. The court reviews your income against published guidelines and either grants the waiver, grants a partial waiver, or denies it.
Pro Tip: Check current filing fees and fee waiver eligibility with your county's Superior Court self-help center before filing. Fees are set locally and can change.
What is Form FL-100 used for?
Form FL-100 is the California Judicial Council Petition, Marriage/Domestic Partnership. It is the document that opens a family law case, whether you are requesting dissolution (divorce), legal separation, or nullity. Filing it is the first formal step in starting your case.
Do I file FL-100 for a legal separation, or only for divorce?
FL-100 is used for all three case types: dissolution, legal separation, and nullity. You select which one you are requesting near the top of the form. Legal separation does not require meeting California's residency requirements, since it does not end the marriage.
What does "irreconcilable differences" mean on FL-100?
Irreconcilable differences is California's no-fault legal ground for divorce. It means the marriage has broken down to the point it cannot be repaired. You do not need to prove wrongdoing by either spouse, and the court does not require details about why the marriage ended.
How much does it cost to file FL-100?
Filing fees for FL-100 generally range from about $435 to $450, depending on the county where you file. This fee is paid to the Superior Court clerk when you submit your Petition and is separate from any cost of preparing your paperwork.
What if I cannot afford the FL-100 filing fee?
You can request a fee waiver by filing Form FW-001, Request to Waive Court Fees, along with your Petition. The court reviews your income against published guidelines and can grant a full waiver, a partial waiver, or deny the request.
Do I need to list my children on FL-100?
Yes, if you and your spouse have minor children together, you must list their names, birthdates, and current residence on FL-100. Doing so also requires filing a UCCJEA declaration, Form FL-105 or GC-120, so the court can confirm it has jurisdiction over custody.
What happens after I file FL-100?
After filing, you must serve the Respondent with the Petition and Summons. The Respondent then has 30 days to file a Response, and California's mandatory 6-month waiting period begins on the date of service. The case cannot be finalized until that period has passed and financial disclosures are complete.
Can I fill out FL-100 myself, or do I need an attorney?
Many people complete and file FL-100 themselves, especially in straightforward, uncontested cases. The form itself is public and free to download, but accuracy matters since it sets the requests the court can later grant. A document preparation service or attorney can help if your situation involves significant assets, custody disputes, or other complications.
How a Document Prep Service Helps With FL-100
Most mistakes on FL-100 don't come from complicated law, they come from small inconsistencies: a wrong date, a missed checkbox, or a form that doesn't match what you'll file later. Virdix is built to catch those before you file:
- Guided questions, plain-language prompts replace confusing legal terms
- Consistency checks, your answers carry through to every related form, including the Summons and UCCJEA declaration
- Complete requests for relief, generated based on what you actually tell us, so nothing gets left blank
- County-specific filing details, including current fee amounts and where to file
We don't replace an attorney for contested or complex cases, but for straightforward filings, Virdix helps make sure your FL-100 is complete and consistent from the start.
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Last updated: July 2026. This article is for informational purposes only and does not constitute legal advice. For advice about your specific situation, consult with a licensed California family law attorney.
Sources: California Courts Self-Help, California Judicial Council, California Family Code