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民法第651条

Termination of Mandate (Agency/Entrustment) Contracts

委任の解除

Plain-language explanation

This article establishes the basic rule for mandate (委任) contracts — agreements where one party entrusts another with handling affairs, such as legal representation, business management, or agency arrangements. Because mandate relationships rely heavily on mutual trust, either party may terminate the contract at any time, without needing a specific reason. This applies to common business relationships like retaining a lawyer, tax accountant, or property manager.

However, this freedom to terminate is not unconditional. If one party terminates at a time that is disadvantageous to the other, or if the mandate also serves the interests of the agent beyond just earning a fee (for example, a distribution or agency arrangement where the agent has a stake in the ongoing relationship), the terminating party generally must compensate the other side for resulting damages. This liability is waived only if there was an unavoidable reason (yamu o enai jiyū) for the termination, such as serious illness, business failure, or other emergencies.

For business owners and lawyers, the key takeaway is the tension between flexibility (either side can walk away anytime) and accountability (walking away badly can trigger damages). Companies frequently modify this default rule through contract clauses specifying notice periods, termination fees, or conditions under which termination is permitted — especially important in long-term consulting, agency, or management contracts where sudden termination could cause significant financial harm to the other party.

日本語での解説

この条文は、委任契約（他人に仕事や事務処理を任せる契約）について、当事者のどちらからでも、いつでも自由に解除できるという原則を定めています。委任は当事者間の強い信頼関係を前提とする契約なので、信頼が失われた場合には理由を問わず契約関係を終了させられるようにしているのです。例えば、顧問契約を結んだ弁護士や税理士との契約、不動産の管理を任せる契約なども、原則としていつでも解約できます。

ただし、自由に解除できるとはいえ、相手に不利なタイミングで一方的に解除した場合や、報酬目的以外に受任者側にもメリットがある委任（例えば代理店契約のように受任者が利益を得る仕組みになっている場合）を解除した場合には、原則として相手の損害を賠償しなければなりません。もっとも、病気や倒産など「やむを得ない事由」があった場合には、損害賠償責任は生じません。

実務上のポイントは、「いつでも解除できる」という柔軟性と、「不利益な解除には賠償責任が伴う」というバランスです。契約書に解除条項や予告期間、違約金の定めを設けることで、この条文が定めるデフォルトルールを修正することが可能です。特に長期契約や受任者に投資的な利益が絡む契約では、解除時のトラブルを避けるため、契約書での事前手当てが重要になります。

Common scenarios

  • ▸A company terminates a consulting or advisory contract with a freelance professional mid-project
  • ▸A business ends an agency or distributorship agreement where the agent also earns commission-based benefits
  • ▸A client dismisses their retained lawyer or tax accountant before a case or filing is complete
  • ▸A property owner cancels a property management contract without prior notice
  • ▸A company faces a damages claim after abruptly terminating a long-term outsourcing arrangement

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Generated by Hanko AI from the official Japanese statute corpus. A general statutory reference for the practising attorney. Confirm the current statute against the facts of your matter.

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