Washington FL Modify 504, the Response to Motion to Allow Testimony (About Modifying Child Support), is the one-page court form you file to tell a Superior Court judge or commissioner whether you agree or disagree that live testimony should be heard at your child support modification hearing. You file it as the responding party after the other parent serves you with Form FL Modify 503, the Motion to Allow Testimony.
This form looks short, but it carries real weight. Washington child support modification hearings normally run on written declarations alone, so this form is your chance to say whether a witness should speak out loud in court. About 9 out of 10 child support cases in Washington decide on paperwork, not live testimony, which makes RCW 26.09.175(6) and this response form the gatekeeper that protects that rule. Miss the deadline or check the wrong box, and you can lose your say on whether a witness gets to shape the judge’s view of your income, your expenses, or your honesty.
Here is what you will learn in this guide:
- 📄 What FL Modify 504 does and exactly who must file it.
- ✅ How to fill out every box, line, and signature block the right way.
- 👨👩👧 Three full filled-out examples using real-life parent scenarios.
- 🏛️ How and where to file it through every channel your county allows.
- ⚠️ The mistakes that get responses rejected and how to dodge them.
What the Form Is and Who Must File It
FL Modify 504 is a mandatory Washington statewide family law form, revised 05/2016, that you use to respond to the other parent’s request for live testimony at a child support modification hearing. The form is approved by the Washington State Administrative Office of the Courts and is filed in the Superior Court for the county where your child support case lives. Always check the bottom of your copy for the 05/2016 revision date so you know you have the current version.
You file this form only if the other parent first files and serves Form FL Modify 503, the Motion to Allow Testimony. That motion asks the court for permission to bring a witness to speak in person, which the law treats as the exception, not the rule. Under RCW 26.09.175(6), the court decides modification motions based on affidavits and written records unless the case is “extraordinary.”
The filer is the responding party, which can be either the Petitioner or the Respondent in the underlying modification case. In plain terms, whoever did not file the motion for testimony is the one who files FL Modify 504. Most filers are self-represented parents, often stressed and reacting to a surprise motion, so this guide is written for you in plain language. Lawyers also use the form, and it includes a signature block for an attorney with their Washington State Bar Association (WSBA) number.
You are never required to file this response. If you do nothing, the judge can still rule on the motion. But filing gives you a voice, and skipping it means the court hears only the moving parent’s side. The plain consequence of silence is that a witness you object to may be allowed to testify without you ever stating why that is unfair.
Before You Start: Documents and Information You Need
Gather your paperwork before you open the form, because every entry on FL Modify 504 must match your existing case records. A mismatch in names or case number can get your response misfiled or rejected, which wastes the few days you have before the hearing. Here is your pre-filing checklist.
- The Motion you were served (FL Modify 503). This tells you what testimony the other parent wants and the exact case caption to copy. Without it, you cannot respond on point, and the court may treat your filing as unrelated.
- Your case number (cause number). This links your response to the right file. A wrong or missing number can route your form to the wrong case and delay the judge from ever seeing it.
- The full names of the Petitioner and Respondent. Copy them exactly as they appear on the Petition. Mismatched names can make the clerk reject the document as not belonging to your case.
- The county where your case is filed. Your response goes to that county’s Superior Court Clerk, not any other county. Filing in the wrong county means it never reaches your judge.
- The hearing date and time. You need this to count your filing deadline backward. Missing the deadline can forfeit your right to be heard on the motion.
- Your county’s Local Court Rules. They set the response deadline and any extra forms. Ignoring them is the top reason responses arrive too late.
- Any written proof or documents supporting your side. You may attach declarations, pay records, or other proof. Without them, your bare check-box response carries less weight.
- A working email and mailing address for service. You must serve a copy on the other party, and you need a reliable address to receive their papers back. A bad address can break the service chain and stall your case.
Take five minutes to confirm each item. The form itself takes only a few minutes to complete once your case details and your decision about testimony are clear in front of you.
Where to Get the Form and How to Access It
You download FL Modify 504 free from the official Washington Courts forms page under the “Petition to Modify Child Support” group, in the section titled To present oral testimony at the hearings. The court posts it in both Word and PDF, and the Word version lets you type your answers before printing. Always download from the courts.wa.gov site so you get the 05/2016 mandatory version and not an outdated copy.
You can also get the form through Washington Law Help, a legal aid site that hosts a guided “fill out online” tool. That tool walks you through each box in question form, then produces a finished PDF you print and sign. This route helps if you find legal forms confusing or want plain-language prompts.
Your county courthouse is a third source. Many Superior Court clerks keep paper copies at the counter, and most counties have a courthouse facilitator who can hand you the form and offer limited help filling it out, though they cannot give legal advice. If you cannot afford a lawyer, call CLEAR at (888) 201-1014 for a referral to low-cost or free legal services.
One nuance: some counties require extra local cover sheets or a specific hearing-notice form beyond the statewide version. Check your county’s Local Court Rules before you file so you do not arrive with an incomplete packet. The plain consequence of skipping local forms is a same-day rejection at the clerk’s counter.
Step-by-Step: How to Fill Out FL Modify 504 Line by Line
FL Modify 504 is one page with a caption block and three short parts: the caption, Item 1 (who you are), and Item 2 (your response), followed by your signature block and an optional lawyer block. Use black ink if filling by hand, write in all caps for names, and copy your case details letter-for-letter from the Petition. Below is every field in the order it appears on the form.
Caption: County, Case Number, and Party Names
The top of the form asks for the Superior Court of Washington, County of ___, the names of the Petitioner/s and Respondent/s “as listed on the Petition,” and the case No. (cause number). This block tells the clerk which case file your response belongs in.
To fill it out, write your county name on the “County of” line, copy the Petitioner and Respondent names exactly as they read on the original Petition, and enter the cause number in the No. box. Match the spelling and order precisely. For example, Maria Lopez enters SPOKANE on the county line, types Maria Lopez as Petitioner and David Lopez as Respondent, and writes No. 24-3-01234-5 in the case-number box.
A common edge case is a name that changed since the original order, such as a parent who remarried. Use the name as listed on the Petition, not your current legal name, so the clerk can match the file. A frequent mistake here is leaving the cause number blank or transposing a digit, which sends your response to the wrong file and keeps the judge from ever seeing it before the hearing. Many filers wrongly believe the clerk will “figure out” which case they mean, but the clerk matches by exact cause number and caption, so any gap stalls the document.
Item 1: I Am the Petitioner or Respondent
Item 1 reads, “I am the (check one): [ ] Petitioner [ ] Respondent in this case.” This box tells the court which party in the existing modification case is responding to the testimony motion.
Check the single box that matches your role on the original Petition. If you started the modification by filing the Petition, you are the Petitioner; if the other parent started it and you are answering, you are the Respondent. For example, David Lopez, who did not file the modification but received Maria’s motion, checks [X] Respondent.
A nuance arises when both parents filed jointly, but on these forms one name is always listed first as Petitioner, so check the role matching the caption. The common mistake is checking the box for the party you think you are based on the testimony motion rather than the underlying Petition, which confuses the court about who is speaking. A widespread misconception is that the parent filing the testimony motion is automatically the “Petitioner” on this form, but your role here comes from the original child support modification Petition, not the motion.
Item 2: Your Response to the Motion
Item 2 is the heart of the form. It says “Response (check one):” and gives three choices: that you agree the court needs to hear testimony to make a fair decision; that the court should not allow testimony because it can decide fairly without it and this is not an extraordinary case; or Other information (if any) with a blank space to explain.
Check only one box, and pick the one that states your true position. If you support live testimony, check the agree box. If you want the hearing decided on the written declarations alone, check the should not allow testimony box, which tracks the standard in RCW 26.09.175(6). If your view is mixed or needs explaining, check Other information and write a short, factual statement in the space. For example, Janet Brooks checks [X] The court should not allow testimony and adds nothing more because the pay stubs already prove income.
The key edge case is the “Other” line: use it when you partly agree, such as accepting testimony on one issue but objecting to a witness on another. Keep your explanation short, factual, and free of insults, because the judge reads it. The most damaging mistake is checking two boxes or none, which makes your position unclear and lets the judge discount your response entirely. A common misconception is that writing a long emotional story in the “Other” box helps; in reality the court weighs whether the case is “extraordinary,” so concise facts about credibility, complexity, or complete records persuade far more than venting.
Declaration Under Penalty of Perjury
Just below Item 2, the form states: “I declare under penalty of perjury under the laws of the state of Washington that the facts I have provided on this form are true.” This line turns your response into sworn testimony, the same as if you spoke under oath.
You do not write anything on the declaration sentence itself; you accept it by signing below. Read it before you sign, and make sure every fact you entered, especially anything in the “Other” box, is true and accurate. For example, Maria Lopez re-reads her “Other” explanation and confirms each statement is correct before she signs.
The nuance is that Washington allows this unsworn declaration in place of a notarized affidavit, so you do not need a notary for FL Modify 504. The serious mistake is entering a false or exaggerated statement, because perjury is a crime and can destroy your credibility on the whole modification. A common misconception is that “penalty of perjury” only applies to in-person testimony, but it applies fully to the words you write on this form.
Signature Block: Signed at, Date, Signature, and Print Name
The signature block asks you to fill in Signed at (city and state), the Date, your signature on the line marked “Person filing Response signs here,” and your printed name. This proves who filed the response and where and when they signed it.
Write the city and state where you physically sign, such as Spokane, WA, enter the date in month/day/year form like 06/03/2026, sign the signature line, and print your full name below. Sign in ink if you printed the form. For example, David Lopez writes Signed at Spokane, WA, dates it 06/03/2026, signs, and prints DAVID LOPEZ.
A nuance: the “signed at” location does not have to be your home city, just the place where you actually sign, which matters if you sign while traveling. The common mistake is forgetting to date or sign the form, which makes it invalid and forces the clerk to reject it. Many filers wrongly think a typed name in the Word version counts as a signature, but you must add an actual signature (handwritten, or a valid electronic signature if your county accepts e-filing).
Lawyer Block (If Any)
The final block, “Lawyer (if any) fills out below,” provides a line for the lawyer’s signature, printed name, and WSBA No. (Washington State Bar Association number), plus the date. This identifies any attorney filing on your behalf.
Leave this block completely blank if you represent yourself. If a lawyer files for you, the lawyer signs, prints their name with their WSBA number, and dates it. For example, when attorney Karen Tate files for David, she signs and prints Karen Tate, WSBA No. 41234.
The nuance is that a “limited representation” lawyer who helps with only this one document may still need to sign here, depending on your fee agreement. The common mistake is a self-represented parent signing on the lawyer line, which misstates the record. A frequent misconception is that having a lawyer help you fill out the form means they must sign it; if they are not formally representing you on this filing, you sign as the self-represented party and leave the lawyer block empty.
Three Filled-Out Examples Using Real Scenarios
Below are three common ways parents complete FL Modify 504, shown as full walkthroughs of one named filer through the whole form. Each table shows what that person enters in each major section.
Scenario 1 — Maria agrees testimony is needed. Maria is the Petitioner who asked to raise child support. The other parent moved for testimony to challenge his income, and Maria agrees a witness will help the judge.
| Form Section | What Maria Enters |
|---|---|
| County of | Spokane |
| Petitioner/s | Maria Lopez |
| Respondent/s | David Lopez |
| Case No. | 24-3-01234-5 |
| Item 1 (role) | [X] Petitioner |
| Item 2 (response) | [X] I agree the court needs to hear testimony |
| Other information | (left blank) |
| Signed at / Date | Spokane, WA / 06/02/2026 |
| Print name | MARIA LOPEZ |
Scenario 2 — David objects and wants a paper decision. David is the Respondent. He believes the pay stubs and worksheets already prove income, so he checks the box opposing testimony and explains the case is not extraordinary.
| Form Section | What David Enters |
|---|---|
| County of | Spokane |
| Petitioner/s | Maria Lopez |
| Respondent/s | David Lopez |
| Case No. | 24-3-01234-5 |
| Item 1 (role) | [X] Respondent |
| Item 2 (response) | [X] The court should not allow testimony |
| Other information | (left blank) |
| Signed at / Date | Spokane, WA / 06/03/2026 |
| Print name | DAVID LOPEZ |
Scenario 3 — Janet partly agrees using the “Other” box. Janet is the Respondent in a King County case. She accepts testimony on her self-employment income but objects to the other parent’s surprise witness on daycare costs.
| Form Section | What Janet Enters |
|---|---|
| County of | King |
| Petitioner/s | Robert Chen |
| Respondent/s | Janet Brooks |
| Case No. | 25-3-04567-1 |
| Item 1 (role) | [X] Respondent |
| Item 2 (response) | [X] Other information |
| Other information | I agree to testimony on my business income only; I object to the daycare witness because the receipts are already in the record. |
| Signed at / Date | Seattle, WA / 06/05/2026 |
| Print name | JANET BROOKS |
A fifth named filer, Aisha Mensah, a single mother in Pierce County, used the “fill out online” tool on Washington Law Help to complete her response objecting to testimony, then printed and signed it the same day.
How to File the Completed Form
You file FL Modify 504 in the same Superior Court where your child support modification case lives, and you must also serve a copy on the other parent or their lawyer. Most counties offer several filing channels. Confirm your county’s options through the Washington Courts directory before you go.
- In person. Take the signed original plus copies to the county Superior Court Clerk’s counter. There is normally no filing fee for a response in an existing case, since the case is already open. Pay any copy fee in cash or card, keep a clerk-stamped copy as your proof of filing, and ask the clerk to “conform” your copy with the filing date.
- By mail. Mail the signed original to the Superior Court Clerk for your county at the courthouse address listed on your county court’s website. Include a self-addressed stamped envelope so the clerk can return a conformed copy. Allow several days, and mail early so it arrives before your deadline; your proof of filing is the returned date-stamped copy.
- E-filing. Many counties, including King and Pierce, use an electronic filing portal (often the Odyssey/eFiling system) reached through the county Superior Court Clerk’s site. E-filing is usually free for this response, accepts card payment for any incidental fees, and gives you an emailed confirmation receipt as proof of filing, often within minutes.
- Service on the other party. Filing is not enough; you must serve a copy on the other parent or lawyer, then file a proof of service such as Proof of Mailing (FL All Family 112). Email service is allowed only if the other party agreed to it in writing.
The single most important timing rule comes from your county’s Local Court Rules. In King County, for example, a response must be filed and served by noon, 5 court days before the hearing (not counting weekends or holidays). Counties differ, so read your local rule and count backward from your hearing date.
What Happens After You File
After you file and serve FL Modify 504, the judge or commissioner reads it along with the other parent’s motion before the hearing. The court then decides whether to allow live testimony under the “extraordinary case” standard in RCW 26.09.175(6). The decision is recorded on Form FL Modify 505, the Order on Motion to Allow Testimony.
If the court agrees with your objection, the hearing proceeds on written declarations alone, and no witness speaks. If the court grants the motion, you will know in advance who may testify and can prepare your own questions or witnesses. Either way, you should attend the hearing, because the court “may not allow you to testify at the motion hearing” if you skip it.
You should keep your conformed copy and proof of service in your case file. If the order allows testimony, gather your documents and think through what you will ask the witness. The practical consequence of a no-testimony order is a faster, paper-based hearing; a testimony order means a longer hearing where credibility may be tested live.
The timeline is usually short, often days, because the motion is tied to your upcoming modification hearing. Watch your mail and email for the signed FL Modify 505 order or a courtroom ruling. Missing that ruling can leave you unprepared for the format of your own hearing.
Mistakes to Avoid When Filling Out the Form
Small errors on a one-page form can still cost you your voice at the hearing. Here are the errors filers make most, with the direct result of each.
- Missing the local deadline. Your response arrives late and the judge may refuse to consider it.
- Filing in the wrong county. The form never reaches your case file and your objection is never read.
- Wrong or blank cause number. The clerk cannot match your response to your case and it sits unfiled.
- Names that do not match the Petition. The clerk may reject the document as not belonging to your case.
- Checking both boxes in Item 2. Your position is unclear and the court may disregard the response.
- Checking no box in Item 2. You file a blank statement that tells the judge nothing.
- Choosing the wrong party role in Item 1. The court is confused about who is responding.
- Forgetting to sign or date. The form is invalid and the clerk rejects it.
- Skipping service on the other party. Your filing is incomplete and the court may not consider it.
- Writing a long emotional rant in “Other.” The judge weighs facts about the “extraordinary case” standard, not feelings, so your point gets lost.
- Assuming you need a notary. You waste time hunting for one when the perjury declaration replaces notarization.
- Using an outdated form version. A non-current form can be rejected; confirm the 05/2016 revision date.
Do’s and Don’ts
Keep these quick rules in mind as you complete and file FL Modify 504.
Do’s
- Do copy your caption exactly from the Petition so the clerk can match your case fast.
- Do read your county’s Local Court Rules first because they set the deadline and any extra forms.
- Do check only one box in Item 2 so your position is crystal clear to the judge.
- Do keep any “Other” explanation short and factual since the court weighs the extraordinary-case standard.
- Do serve the other party and file proof because filing alone does not complete the step.
- Do keep a conformed copy as your proof of filing in case a dispute arises.
Don’ts
- Don’t miss the filing deadline or you may forfeit your say on testimony.
- Don’t leave Item 1 or Item 2 blank because an unclear form gives the judge nothing to weigh.
- Don’t sign without re-reading your facts since you sign under penalty of perjury.
- Don’t insult the other parent in writing because the judge reads every word.
- Don’t file in a county other than your case county or the form never reaches your judge.
- Don’t use an old form version when the current 05/2016 mandatory form is free online.
Pros and Cons of Filing on Your Own vs. With Help
Many parents complete FL Modify 504 alone because it is short, but some hire limited-scope help when the stakes are high. Here is how the two paths compare.
Filing on your own (pros and cons)
- Pro: It is free beyond small copy costs, since there is normally no filing fee for a response.
- Pro: The form is short and plain, with only two check-box items and a signature.
- Pro: Free guided tools like Washington Law Help walk you through each box.
- Pro: You stay in full control of how you state your position in the “Other” box.
-
Pro: Same-day filing is possible through e-filing or the clerk’s counter.
-
Con: You may misjudge the “extraordinary case” standard and check the wrong box.
- Con: A missed deadline or service step can void your effort.
- Con: No one reviews your wording before the judge reads it.
Filing with a lawyer’s help (pros and cons)
- Pro: A lawyer frames your objection to match the RCW 26.09.175(6) standard.
- Pro: They confirm the deadline and service so nothing is missed.
- Pro: Limited-scope help can be cheaper than full representation.
- Pro: They can prepare you for live testimony if the motion is granted.
-
Pro: Their WSBA signature signals seriousness to the court.
-
Con: It costs money that many parents in support disputes cannot spare.
- Con: Scheduling a lawyer takes time you may not have before the hearing.
- Con: For a simple agree/disagree response, the cost may outweigh the benefit.
FL Modify 503 vs. FL Modify 504
These two forms are a matched pair, and confusing them is common. The table below shows the difference.
| FL Modify 503 (Motion) | FL Modify 504 (Response) |
|---|---|
| Filed by the parent requesting live testimony | Filed by the parent responding to that request |
| Argues the case is “extraordinary” and lists reasons | States whether you agree or object to testimony |
| Three pages with detailed reason boxes | One page with two check-box items |
| Must be scheduled for a hearing by the filer | Filed and served by your county’s response deadline |
FAQs
Do I have to file FL Modify 504 if I got served with a Motion to Allow Testimony?
No. Filing is optional, but if you stay silent the judge hears only the other parent’s side, so filing protects your right to object to testimony at the hearing.
Is there a filing fee for FL Modify 504?
No. There is normally no fee because you file it in an existing, already-open child support case rather than starting a new case.
Do I need a notary to sign this form?
No. The form includes a declaration under penalty of perjury under Washington law, which replaces the need for notarization.
Can I check both boxes in Item 2 if I partly agree?
No. Check only one box; if your view is mixed, check the “Other information” box and briefly explain what you agree to and what you object to.
Do I write my current name or the name on the Petition in the caption?
No, not your new name. Use the party names exactly as listed on the original Petition so the clerk can match your response to the correct case file.
Which box do I check in Item 1 if the other parent filed the testimony motion?
No automatic rule from the motion. Check the role you hold on the underlying child support Petition, Petitioner or Respondent, not based on who filed the testimony motion.
Can I e-file FL Modify 504?
Yes. Many Washington counties, including King and Pierce, accept e-filing through the county Superior Court Clerk’s electronic portal, and you receive an emailed confirmation as proof.
Is filing the form the same as serving it on the other parent?
No. Filing and serving are separate steps; you must give a copy to the other parent or their lawyer and then file a proof of service.
What is the deadline to file my response?
Yes, there is one, set by your county’s Local Court Rules; in King County, for example, it is noon, 5 court days before the hearing, not counting weekends or holidays.
Do I have to attach documents to FL Modify 504?
No. Attachments are optional, but written proof such as pay records can strengthen your position, and the form lets you file other written support for your side.
Does checking “should not allow testimony” mean I skip the hearing?
No. You should still attend, because the court may rule on the motion at the hearing and may not let you speak if you do not appear.
What law controls whether testimony is allowed?
Yes, one statute controls: RCW 26.09.175(6), which says modification motions are decided on written records unless the case is extraordinary.
Can a lawyer help me with just this one form?
Yes. Washington allows limited-scope representation, so a lawyer can help with only FL Modify 504, and if they formally represent you on it they sign the lawyer block with their WSBA number.
Where do I get the official current version of the form?
Yes, from one place: the Washington Courts forms page, which hosts the mandatory 05/2016 version in both Word and PDF for free.
Related reading
- How to Fill Out California Form FL-700 (w/Examples) + FAQs
- How to Fill Out Washington Form FL All Family 131 (w/Examples) + FAQs
- How to Fill Out Washington Form FL Parentage 301 (w/Examples) + FAQs
- How to Fill Out Washington FL Modify 521 (w/Examples) + FAQs
- How to Fill Out Washington FL Modify 601 (w/Examples) + FAQs
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- How to Fill Out California Form FL-120 (w/Examples) + FAQs