Arbitration in Japan: law, the JCAA Rules, costs and enforcement

The short version

• The statute is the Arbitration Act (Act No. 138 of 2003), in force since 1 March 2004 and based on the Model Law of the United Nations Commission on International Trade Law (UNCITRAL). It was amended by Act No. 15 of 2023, in force from 1 April 2024.
• The Japan Commercial Arbitration Association (JCAA) administers most international cases seated in Japan, under its Commercial Arbitration Rules 2021, its Interactive Arbitration Rules 2021 and its Administrative Rules for UNCITRAL Arbitration 2021, all effective from 1 July 2021.
• The default tribunal is three arbitrators. A JCAA case has a nine-month target for the award, and an expedited award, for claims of JPY 300,000,000 or less, is due in three or six months.
• The 2023 reform lets a court enforce a tribunal’s interim measures and waive the Japanese translation of an award, and it added the Tokyo and Osaka District Courts as venues.
• An award has the same effect as a final and binding judgment. It cannot be appealed on the merits and can only be set aside on the Article 44 grounds, within three months of receipt.
• Foreign awards are enforced under the New York Convention, which Japan joined in 1961 with the reciprocity reservation. Neither the Arbitration Act nor the JCAA Rules mention AI.^{1,3,4,5,10,17,18}

What law governs arbitration in Japan?

The Arbitration Act (Act No. 138 of 2003) governs international arbitration in Japan. Article 1 says that arbitration procedures “of which the place of arbitration is in Japan” are governed by the Act. The place of arbitration, called the seat, is the arbitration’s legal home: its law governs the procedure and its courts supervise the case. Most of the Act applies where the seat is in Japan (Art 3(1)).¹

The Model Law is UNCITRAL’s 1985 template for national arbitration laws, amended in 2006. The Act is based on it, and UNCITRAL lists Japan with the 2006 amendments. The same text covers domestic and international cases, so Japan has one arbitration statute, not two.^1,18

A tribunal can rule on its own jurisdiction, meaning its power to hear the dispute (Art 23(1)). If it rules in a separate decision that it has jurisdiction, a party has 30 days to ask a court to review that ruling, and the tribunal can carry on meanwhile (Art 23(5)).¹

Japan acceded to the New York Convention, the 1958 treaty on recognising and enforcing foreign arbitral awards, on 20 June 1961, with effect from 18 September 1961. It applies the Convention only to awards made in another contracting state, a limit known as the reciprocity reservation.¹⁷

Why do parties choose Japan as a seat?

Japan draws parties with a Model-Law arbitration statute, and the government actively promotes it as a seat. Because the parties, then the tribunal, choose the language (Art 30), a Japan-seated case can run in English. The government runs Japan International Arbitration Week, held from 21 to 25 July 2026 in Tokyo and Kyoto. The 2026 week was organised by the Ministry of Justice, the Ministry of Economy, Trade and Industry, the Japan Association of Arbitrators, the JCAA and the Japan Federation of Bar Associations, with UNCITRAL.^1,7,9,18

Japan is open to foreign participants. Foreign counsel may represent a party in an international arbitration case under the Foreign Lawyers Act (Act No. 66 of 1986, Art 2(xiv)). That term covers cases where a party is based abroad, where the law the tribunal applies is not Japanese, or where the seat is abroad. There is no nationality restriction on counsel or arbitrators, and an arbitrator need not be a qualified lawyer.^8,9

Japan is a smaller arbitration market than its neighbours. Arbitration is used there less than court litigation, and the international caseload is comparatively small. Of the international cases that do choose Japan as a seat, the JCAA takes more than any other local body. In the 2025 International Arbitration Survey by Queen Mary University of London, Japan was not among the seats respondents named most often. For the seats they did name, see arbitration in Singapore and arbitration in Hong Kong.^9,20

Which institutions run arbitrations in Japan, and under what rules?

The JCAA is the main institution. It has three rule sets, all effective from 1 July 2021: the Commercial Arbitration Rules 2021, the Interactive Arbitration Rules 2021, under which the tribunal shares its preliminary views with the parties, and the Administrative Rules for UNCITRAL Arbitration 2021. The JCAA does not scrutinise or approve draft awards before they are issued. For the AI picture across bodies, see the AI rules tracker.^3,4,5

Other bodies handle narrower work. Shipping cases can go to the Tokyo Maritime Arbitration Commission, run by the Japan Shipping Exchange. Domestic disputes often go to the centres run by local bar associations, which commonly try mediation first. Construction has its own forum, the Construction Dispute Review Boards, which the Construction Business Act created. We found no openable official figure for the JCAA’s current annual caseload.^3,9

What should the arbitration clause say, and what can be arbitrated?

The JCAA publishes a model clause: “All disputes, controversies or differences arising out of or in connection with this contract shall be finally settled by arbitration in accordance with the Commercial Arbitration Rules of The Japan Commercial Arbitration Association. The place of the arbitration shall be [city and country].” Any civil dispute the parties can settle may be arbitrated, except divorce and the dissolution of an adoptive relation (Art 13(1)). Name the seat and the language in the clause, because the Act lets the parties and then the tribunal decide them (Arts 28, 30).^1,3

The agreement must be in writing, with broad deeming rules. A signed document, an exchange of letters or an electronic record all count (Art 13(2) to (4)). The 2023 amendment added Art 13(6), which deems a clause in a document or electronic record incorporated into a contract not concluded in writing to be “made in writing.”¹

• Carve-outs: a consumer may cancel an arbitration agreement that covers future disputes with a business, and an arbitration agreement covering future individual labour disputes is void (Supplementary Provisions, Arts 3 and 4).
• Default tribunal: three arbitrators where two parties do not agree otherwise (Art 16(2)). An arbitrator owes a continuing duty to disclose circumstances that raise doubts about impartiality or independence (Art 18(3), (4)).^1,2

On confidentiality, the Act is silent. It imposes no general duty to keep an arbitration confidential, so parties who want one should write it into the clause or adopt institutional rules that provide it.^1,9

How does a JCAA arbitration work, step by step?

A Japan-seated arbitration starts when one party notifies the other that the arbitration procedure applies to the dispute (Art 29(1)). That notice also postpones and renews the prescription period, the time limit for bringing the claim (Art 29(2)). Each side then appoints an arbitrator, and the two appointees pick the third. If a party or the two arbitrators miss the 30-day window, a court appoints on request (Art 17(2)). The Act provides no emergency arbitrator for urgent relief before the tribunal is formed; the JCAA offers one under its Commercial Rules (Arts 75 to 77).^1,3

The tribunal must treat the parties equally and give each a full chance to present its case (Arts 25, 26). Within those limits the parties set the procedure, the place and the language (Arts 28, 30). The tribunal can order five kinds of interim measure, such as preserving assets or preserving evidence. It can grant one on a prima facie showing, meaning a case that looks sound on its face, and can require security in return (Art 24(1) to (3)). An order compensating a party for a wrongly granted measure “has the effect of an arbitral award” (Art 24(8), (9)).¹

The award must be in writing, signed and dated, must state the place of arbitration and must give reasons unless the parties agree otherwise (Art 39). A settlement can be recorded as a consent award. In an expedited case the tribunal is a sole arbitrator unless the parties agree on three, and the proceedings are usually documents-only (Commercial Rules Arts 86, 87).^1,3

How long does arbitration in Japan take, and what does it cost?

In a standard JCAA case the tribunal “shall use reasonable efforts to render an arbitral award within nine months” of being constituted (Commercial Rule 43.1). The expedited procedure applies where the amount in dispute, claims and counterclaims and set-off together and excluding interest and costs, is JPY 300,000,000 or less, or where the parties agree to it (Rule 84.1). The expedited award is then due within six months, or within three months where the amount in dispute is JPY 50,000,000 or less (Rule 88).³

Cost turns mainly on the amount or economic value of the claim, which the Rules work out per claim with one year’s interest added (Rule 92). The claimant pays a fixed administrative fee by band on filing, plus consumption tax; that fee is a set amount, not a maximum (Rule 103). Where the value cannot be calculated, it is deemed to be JPY 70,000,000 (Rule 103.2). Each arbitrator is paid by the hour at JPY 50,000, reduced by 10% for every 50 hours over 150 and by at most half overall, subject to an upper limit set by band that cannot be exceeded (Rules 93, 94, 95). A three-member tribunal pays the presiding arbitrator 120% of the sole-arbitrator limit and each co-arbitrator 80% (Rule 94.3).³

• Costs of the arbitration: the administrative fee, the arbitrators’ remuneration and expenses, and the parties’ counsel and expert fees the tribunal finds reasonable; the tribunal apportions them (Rule 80).
• Worked example, JPY 300,000,000 in dispute: the administrative fee is JPY 1,900,000, which is 1,300,000 plus 0.3% of the 200,000,000 above 100,000,000. A sole arbitrator’s remuneration is capped at JPY 7,000,000, which is 4,000,000 plus 1.5% of that 200,000,000.
• Duration: the only openable figure is historic. For JCAA cases concluded from 2011 to 2020, the average time from the tribunal being constituted to the award was about 12.8 months, and 22 of 139 cases were expedited, averaging about 3.5 months.^3,6

What role do Japanese courts play during an arbitration?

A court may act in an arbitration only where the Act allows (Art 4). On venue, a petition goes to the court the parties agreed, the court for the place of arbitration, or the respondent’s general venue (Art 5(1)). The 2023 amendment added Art 5(2), which lets a party file in the Tokyo or Osaka District Court where the seat is in Japan, concentrating arbitration work in two courts.¹

A court can grant a provisional order to protect a party despite an arbitration agreement (Art 15), and it can help take evidence. In practice remote hearings are conducted in Japan-seated cases, especially for procedural hearings. We cite no specific judgment: the court judgment database was in maintenance on 30 October 2026.^1,9

Can you set aside an arbitral award in Japan?

There is no appeal on the merits. The only route is to set aside the award under Article 44, which means a court at the seat cancels it. The eight grounds track Model Law Article 34 and New York Convention Article V: incapacity, an invalid agreement, lack of proper notice, inability to present a defence, an award beyond the scope of the submission, improper composition or procedure, a non-arbitrable subject, and conflict with public policy. The last ground applies where “the content of the arbitral award is contrary to public policy in Japan” (Art 44(1)(viii)).¹

The time limit is firm. A set-aside petition cannot be filed once three months have passed from receipt of the award copy, or once an enforceability order has become final (Art 44(2)). The court must hold an oral argument or a hearing both sides can attend before deciding, a partial set-aside is possible, and an immediate appeal lies against the decision (Art 44(4), (6), (7)).¹

How are arbitral awards enforced in and from Japan?

An award “has the same effect as a final and binding judgment,” whether or not the seat is in Japan (Art 45(1)). To enforce it the winning party asks a court for an enforceability order (Art 46(1)). The court must grant it unless a refusal ground applies; those grounds, in Art 45(2), follow the New York Convention. The 2023 amendment lets the court, after hearing the respondent, dispense with a Japanese translation of all or part of the award (Art 46(2) proviso), and it added the Tokyo and Osaka District Courts as venues (Art 46(4)).¹

The 2023 amendment also made a tribunal’s interim measures enforceable. A party can ask a court for an enforcement-approval order, and the court can order a payment penalty where the other side breaches the measure, whatever the seat (Arts 47 to 49). Here too the court may dispense with a Japanese translation (Art 47(2)).¹

A Japanese award is enforced abroad under the New York Convention, the 1958 treaty on recognising and enforcing foreign arbitral awards, which has 172 parties; see New York Convention grounds. To enforce a Japanese award into Singapore, see arbitration in Singapore.¹⁷

What changed in 2023, and what is pending?

Two Acts modernised Japan’s private dispute-resolution law. The Act partially amending the Arbitration Act (Act No. 15 of 2023) and the Act implementing the Singapore Convention on Mediation (Act No. 16 of 2023) were promulgated on 28 April 2023 and took effect on 1 April 2024. The Ministry of Justice says the aim was to bring Japan into line with the latest international standards.¹⁰

Japan acceded to the Singapore Convention on Mediation, the 2018 United Nations treaty on enforcing international mediated settlements, on 1 October 2023, in force for Japan on 1 April 2024. Japan made the opt-in reservation, so the Convention applies only where the parties have agreed to it. The implementing Act (Act No. 16 of 2023) lets a court order enforcement of an international mediated settlement and excludes consumer, individual-labour and family matters and settlements already enforceable as a judgment or award.^11,19

One procedural reform is still pending. A court-digitalisation measure (Act No. 53 of 2023) has a part not yet in force, scheduled by 13 June 2028. It touches how petitions are filed, not the substance of arbitration.²

What does Japan say about AI in arbitration?

Japan has a national AI law, but it says nothing about arbitration. The Act on the Promotion of Research, Development and Utilisation of AI-Related Technologies (Act No. 53 of 2025) was promulgated and came into force on 4 June 2025, except its chapters on the AI Basic Plan and the AI Strategy Headquarters, which came into force on 1 September 2025. It is a framework law: it sets basic principles (Art 3), provides for an AI Basic Plan (Art 18) and an AI Strategy Headquarters set up in the Cabinet and chaired by the Prime Minister (Arts 19, 22), and imposes no binding obligations. The Cabinet Office handles the Headquarters’ work.^12,13

The courts are cautious. At the Chief Justice’s Constitution Memorial Day press conference in May 2025, the court called using AI for administrative work “quite conceivable.” It warned, though, that AI poses security risks, that its data reliability is “often questionable,” and that it could infringe copyright. A world where AI replaced the whole decision-making process was, in the court’s words, “something like a science fiction world.” The court said it would “continue to monitor the situation with great interest and caution.” Its 2026 addresses treat AI as a force for change and call for a flexible structure that can keep pace.^14,15

The Ministry of Justice issued a guideline in August 2026 on AI legal-work support services and the Attorney Act Article 72 monopoly on legal services. It addresses AI legal services in general, not arbitration, and supplements a 2023 guideline. Neither the Arbitration Act nor the JCAA Rules mention AI.^1,3,16

For how arbitral practice treats AI, see AI in arbitration and, for the region, AI in dispute resolution in South-East Asia, the nearest regional guide. For how a neighbouring Asian seat’s main institution approaches AI, see SIAC and AI. For how courts elsewhere have handled awards challenged over AI use, see AI and setting aside awards. A tribunal cannot hand its decision to a machine; that is the rule of non-delegation. A case invented by AI is a hallucination. We suggest raising AI tools and recording what is agreed in Procedural Order No. 1.¹

What is still open in Japan arbitration?

• Whether the JCAA will publish AI guidance, and how the 2025 AI framework law and the courts’ statements will reach arbitral tribunals.
• How courts apply the new interim-measure enforcement route and the translation waiver in practice since 1 April 2024. We found no openable decision.
• The JCAA’s current annual caseload. The only openable figures run to 2020.
• The court-digitalisation part of Act No. 53 of 2023, due by 13 June 2028.^1,2,6,12,14