Best Efforts vs. Reasonable Efforts Clauses: Understanding Performance Standards
Про вибір застереження: максимальні зусилля проти розумних зусиль розповіла кандидат юридичних наук, доцент Чернівецький національний університет імені Юрія Федьковича Оксана Кіріяк під час заходу з підвищення професійного рівня адвокатів, що відбувся у Вищій школі адвокатури НААУ.
Кіріяк Оксана
11.09.2025

Лектор докладно проаналізувала разом з учасниками вибір застережень, а саме:

1. Understanding Efforts Clause in Legal English – загальна характеристика.

2. Exploring Efforts Clause in Legal Writing – застереження у юридичному документообігу.

3. Efforts Clause in Legal Negotiations and Advocacy – ідіоми у юридичному дискурсі.

4. Resources for Further Learning – корисні посилання для поглиблення знань.

У рамках характеристики застережень акцентовано на наступному:

1. Understanding Efforts Clause in Legal English – загальна характеристика

Best Efforts: Implies a higher duty of diligence, requiring a party to take all necessary and commercially reasonable actions to achieve the intended result.

Reasonable Efforts: Imposes a less stringent standard, meaning the obligated party must take practical, commercially feasible steps but is not required to go beyond industry norms.

The Importance of "Best Efforts" and "Reasonable Efforts" Clauses in Contracts:

Efforts clauses, such as "best efforts" and "reasonable efforts,"play a crucial role in commercial contracts, M&A transactions, and regulatory compliance, defining the level of diligence required from parties without guaranteeing a specific outcome.

Key Takeaway: Well-drafted efforts clauses ensure contractual clarity, reduce enforcement risks, and provide legal certainty, making them a critical tool in contract negotiation and dispute resolution.

2. Exploring Efforts Clause in Legal Writing – застереження у юридичному документообігу

Efforts Clauses Compared:

  • Best Efforts Clause:

The Distributor shall use its best efforts to obtain all necessary licenses, permits, and approvals required for the marketing and sale of the Products in the Territory, including pursuing all available legal and administrative remedies in the event of a denial.”

  • Reasonable Efforts Clause:

The Supplier shall use reasonable efforts to deliver the Goods by June 30, 2025, taking into account factors such as availability of raw materials, standard shipping delays, and other circumstances beyond its reasonable control.”

  • Commercially Reasonable Efforts Clause:

The Licensee shall use commercially reasonable efforts to promote and market the Licensed Software in the Territory, consistent with practices normally employed by similarly situated companies in the software industry.”

3. Efforts Clause in Legal Negotiations and Advocacy – ідіоми у юридичному дискурсі

Some Linguistic notes:

  • Modifiers: (1) best; (2) reasonable.

  • Intensifiers: (1) utmost; (2) commercially.

  • Contextual Adverb: (1) diligently; (2) consistently; (3) continually.

  • Synonyms and Related Terms: (1) endeavors; (2) undertakings; (3) attempts.

4. Resources for Further Learning – корисні посилання для поглиблення знань

Drafting Best Practices:

1) Avoid ambiguity by defining specific actions required under the clause.

2) Consider adding performance benchmarks (e.g., market comparisons, timeframes, regulatory standards).

3) Clarify exceptions and limitations (e.g., financial constraints, force majeure).

Cases & Regulations:

  • Muller v. Oregon, 208 U.S. 412 (1908).

Thе Court tооk judicial cognizance of all matters of general knowledge such as the fact that woman's physical structure and the performance of maternal functions place her at a disadvantage which justifies a difference in legislation in regard to some of the burdens which rest upon her.

  • Sheffield District Railway Co v Great Central Railway Co (1911).

Core Matter:

  1. The Great Central Railway had agreed to use its “best endeavours” to direct traffic onto the Sheffield District line.

  2. When traffic failed to materialize, the dispute centered on whether “best endeavors” meant guaranteeing a result or merely making genuine efforts.

The Court of Appeal held that “best endeavours” does not amount to a guarantee of success. It requires the promisor to take all reasonable steps within its power to fulfill the contractual objective.

The key outcome is that a contractual obligation to use “best endeavours” does not mean guaranteeing success, but rather requires a party to take all reasonable and practical steps available to them to try to achieve the promised result.

  • Spain v. Phoenix Electric, 2024

Tend to differentiate best efforts vs. reasonable efforts, requiring proof of additional diligence for best efforts clauses.

  • Rhodia International Holdings v. Huntsman, 2007.

Often interpret efforts clauses in context rather than treating them as rigid legal standards.

  • Himawan v. Cephalon, Inc., 2024

A notable Delaware Court of Chancery case addressing "best efforts" clauses is Himawanv. Cephalon, Inc., decided on April 30, 2024. In this case, the court examined whether Cephalonfulfilled its contractual obligation to use "commercially reasonable efforts" in developing a pharmaceutical product post-merger. The court concluded that Cephalonacted within its rights, emphasizing that "commercially reasonable efforts" do not mandate pursuing development when clinical results are unfavorable. This decision underscores the importance of clearly defining effort standards in contracts and highlights how Delaware courts interpret such clauses in the context of business realities.

  • Article 8(3) of the Rome I Regulation.

When assessing contractual obligations such as efforts clauses, courts may apply overriding mandatory provisions of the law of the country where performance occurs, which can impact how efforts obligations are enforced in cross-border contracts.