Child Support in Japan After the 2026 Reform: Evidence to Keep (Agreements, LINE, Bank Records) and How to Collect Unpaid Support

Last reviewed October 19, 2026 · 8 min read · By the PEA team (Lumina Spark)

日本語版 (Japanese version)

Short answer: Decide the amount, payment period, payment day and bank account, and put it in writing. Japan's Ministry of Justice (MOJ) says letters, email, social media messages and bank records showing payments made as agreed can also be evidence. Since April 1, 2026, a parent can apply to seize unpaid support based on the written arrangement the parents made, without a court award, and a parent who divorced without agreeing on support can claim statutory child support. Keep messages and records, and get advice early if payments stop. This article is general information based on Japanese law and official guidance as of October 2026, not legal advice.

What changed on April 1, 2026

The Act partially amending the Civil Code on child-rearing after divorce (Act No. 33 of 2024) came into effect on April 1, 2026. For child support, the main changes are:

ChangeWhat it meansNote
Statutory lienYou can apply to seize child support based on the document the parents made when they arranged it, even without a notarial deed or mediation record, up to 80,000 yen per child per monthApplies to monthly amounts arising on or after April 1, 2026. The court may ask for material showing the other parent actually made the document
Statutory child supportIf you divorced without agreeing on support, the parent with primary custody can claim 20,000 yen per child per month from the date of divorce (Civil Code Article 766-3 and an MOJ ordinance)Only for divorces on or after April 1, 2026. Courts say this amount is not a standard for child support
One-application enforcementOne application to a district court can start asset disclosure, an order for information such as the employer, and seizure of wages, in sequenceApplies to applications made on or after April 1, 2026

Statutory child support lasts until the earliest of the date the parents agree on, the date a court ruling becomes final, or the child turning 18. The paying parent can refuse all or part if they prove they can't pay or that paying would make their life extremely hard. Because courts say the amount isn't a standard, it's best to agree on support through discussion or family court mediation.

Put the agreement in writing

MOJ's English guidance says divorcing parents should decide the amount, the period, the timing and the method of payment, such as the bank account, and that "this agreement should be written, not in the form of an oral promise." MOJ publishes a model agreement (the co-parenting plan form).

  • What to write: each child's name, the monthly amount per child, the payment period, the monthly payment day and the bank account. Houterasu says the agreement doesn't have to be an official document, but these points must be clear and the document must be genuine.
  • Signatures: MOJ recommends a document signed and sealed by both parents, and says that if a registered seal is used, getting the seal registration certificate is also worth considering.
  • For the strongest position: a notarial deed that includes the debtor's consent to compulsory execution, a family court mediation record, or a court ruling lets you apply for compulsory execution directly.

What can count as evidence

MOJ's guidance on the co-parenting plan says that, besides a signed and sealed document, letters, email, social media messages and records showing payments were made as agreed (a bank book) can also be evidence.

What you need to showWhat may help
What was agreedA signed agreement, a notarial deed, a mediation record or ruling, emails or messages showing the terms
That payments were made (or used to be)Bank book and transfer records; for cash handed over, a record of the date and amount received
That payments stoppedBank records, messages asking for payment and the other parent's replies
That the child lives with you (statutory child support)Your resident record; if it doesn't show this, records of ongoing contact with a nursery or school, or a lease (Tokyo District Court)

No official source mentions LINE by name; "social media messages" is as specific as MOJ gets.

Keeping LINE and email messages

  • Don't delete chats about child support, and back up your chat history.
  • Take full-screen screenshots that show the other person's name or account and the date, including the messages before and after.
  • Screenshots can be dismissed as fabricated. Fixing the file on the day you take it, in a form a third party can check (for example with a trusted timestamp), gives you something to answer that with.
  • Messages alone may not show that the other parent personally agreed. Put important arrangements in a document both parents sign.

When support isn't paid

  1. Ask for payment and keep the exchange. For a written demand, you can use certified-content mail (naiyō shōmei).
  2. Seize based on the written arrangement (for amounts from April 2026): up to 80,000 yen per child per month can be seized based on the document the parents made, without a notarial deed or mediation record. The court may ask for material showing the other parent made it, such as a document they signed and sealed.
  3. Compulsory execution: with a notarial deed containing consent to execution, a mediation record or a ruling, you can apply for compulsory execution. Since April 2026, one application can start asset disclosure, an information order and wage seizure in sequence. Up to half of take-home pay can be seized.
  4. Family court mediation: if nothing was agreed, or you want to change the agreement, apply for child support mediation at the family court for the other parent's address (or one you both agree on). The fee is 1,200 yen in revenue stamps per child plus postage stamps. Unpaid statutory child support can be included.

Time limits

  • Support agreed between the parents: Houterasu says 5 years from when payment fell due (5 years even if it was in a notarial deed).
  • Support set by mediation or a court ruling: Houterasu says 10 years, but the Civil Code says the 10-year rule doesn't apply to amounts not yet due when the mediation or ruling became final (Article 169(2)). Monthly amounts falling due afterwards appear to stay at 5 years, so check with a lawyer.

Older months expire first, so don't wait.

Where to get help

ServicePhone and hours (as of October 2026)Notes
Child Support and Parent-Child Contact Consultation Support Center (commissioned by the Children and Families Agency)0120-965-419 (from mobiles 03-3980-4108). Weekdays except Wednesday 10:00–20:00, Wednesday 12:00–22:00, Saturdays and holidays 10:00–18:00In Japanese. Counselors are not lawyers
Houterasu Multilingual Information Service0570-078377. Weekdays 9:00–17:00Information on legal systems and consultation services in several languages
Family courtThe court for the other parent's address, among othersApplications for child support mediation

About PEA

When you check a screenshot, PEA seals the file's hash with a digital signature and a timestamp from an external time-stamping authority. If you turn the result into a certificate, the other parent or a lawyer can enter the certificate number to confirm the image existed when you checked it and hasn't changed since. PEA also checks for signs of AI generation or editing and shows whether details such as the date are visible.

PEA can't prove an agreement was made or that a conversation really happened, and a certificate is not a document you can use for seizure or compulsory execution. The first check is free and in English, with no account: try a free check.

Frequently asked questions

Can a child support agreement made over LINE be used as evidence in Japan?

Japan's Ministry of Justice says that, besides a signed and sealed document, letters, email, social media messages and bank records of payments made as agreed can be evidence. But messages alone may not show that the other parent personally agreed. Put the amount, period, payment day and account in a document both parents sign.

What if we divorced in Japan without agreeing on child support?

For divorces on or after April 1, 2026, the parent with primary custody can claim statutory child support of 20,000 yen per child per month from the date of divorce (Civil Code Article 766-3). It ends at the earliest of an agreed date, a final court ruling, or the child turning 18. Courts say the amount isn't a standard, so agree on support through discussion or family court mediation.

What can I do if my ex stops paying child support in Japan?

For amounts arising from April 2026, you can apply to seize up to 80,000 yen per child per month based on the written arrangement you made, even without a court award; the court may ask for proof the other parent made the document. With a notarial deed, mediation record or ruling you can apply for compulsory execution, and one application can now start asset disclosure through wage seizure.

How far back can I claim unpaid child support in Japan?

Houterasu says 5 years for support agreed between the parents and 10 years for support set by mediation or a ruling. The Civil Code limits the 10-year rule to amounts already due when the mediation or ruling became final (Article 169(2)), so check with a lawyer which months fall under which limit.

Sources