Impossibility of performance

The doctrine^[1] of impossibility or impossibility of performance or impossibility of performance of contract is a doctrine in contract law.

In contract law, impossibility is an excuse for the nonperformance of duties under a contract, based on a change in circumstances (or the discovery of preexisting circumstances), the nonoccurrence of which was an underlying assumption of the contract, that makes performance of the contract literally impossible.

For example, if Ebenezer contracts to pay Erasmus £100 to paint his house on October 1, but the house burns to the ground before the end of September, Ebenezer is excused from his duty to pay Erasmus the £100, and Erasmus is excused from his duty to paint Ebenezer's house; however, Erasmus may still be able to sue under the theory of unjust enrichment for the value of any benefit he conferred on Ebenezer before his house burned down.

The parties to a contract may choose to ignore impossibility by inserting a hell or high water clause, which mandates that payments continue even if completion of the contract becomes physically impossible.

Sometimes it is impossible to perform a contract as a result of war.^[2]

Australia

Frustration usually involves impossibility of performance.^[3] As to whether the non-existence of the subject matter of a contract constitutes (initial) impossibility of performance, see McRae v Commonwealth Disposals Commission.^[4] Cf. Res extincta.

England and Wales

A contract may be frustrated by impossibility of performance.^[5]

In 1997, Downes said that impossibility and impracticability were separate in England and Wales, and that impracticability was not usually found to result in frustration.^[6]

The English case that established the doctrine of impossibility at common law is Taylor v Caldwell.^[7]

New Zealand

Wilkins and Davies Construction Co Ltd v Geraldine Corporation [1958] NZLR 985 is relevant.^[8]

South Africa

A contract may be ended by supervening impossibility of performance.^[9]

United States

At common law, for the defence of "impossibility" to be raised performance must not merely be difficult or unexpectedly costly for one party, there must be no way for it to actually be accomplished. However, in the United States it is beginning to be recognized that "impossibility" under this doctrine can also exist when the contemplated performance can be done but only at an excessive and unreasonable cost, i.e., commercial impracticability.^[10] On the other hand, some US sources see "impossibility" and impracticability as being related but separate defences.

References

Roy Granville McElroy. Impossibility of Performance: A Treatise on the Law of Supervening Impossibility of Performance of Contract, Failure of Consideration, and Frustration. Cambridge, at the University Press. 1941. Google
Rudolf Gottschalk. Impossibility of Performance in Contract. Stevens & Sons Ltd. London. 1938. With a supplement for the years 1938-1944. Stevens & Sons. London. 1945.
"Impossibility and Mistake". Halsbury's Laws of England. Fifth Edition. Volume 9(1). Paragraph 888 et seq. Fourth Edition. Reissue. 1998. Volume 9(1). Chapter 7. Paragraph 888 at page 644 et seq.
S Martin Leake. "Impossibility of Performance". A Digest of Principles of the Law of Contracts. Third Edition. Stevens and Sons. 1892. Page 590.
William R Anson. "Impossibility of Performance". Principles of the English Law of Contract. Sixth Edition. Oxford, at the Clarendon Press. 1891. Part 5. Chapter 4. Pages 317 to 321.
Frederick Pollock. "Impossible Agreements". Principles of Contract. Fifth Edition. Stevens and Sons. 1889. Chapter 8. Page 378.
William T Brantly. "Impossibility of Performance". Law of Contract. Second Edition. M Curlander. 1912. Chapter 4. Page 418.
John D Lawson. "Discharge by Impossibility of Performance". The Principles of the American Law of Contracts at Law and in Equity. 1893. Chapter 13. Page 457.
John D Lawson. "Impossibility of Performance". Rights, Remedies and Practice. 1890. Volume 5. Chapter 119. Page 4166.
Charles Fisk Beach. "Impossible Contracts". A Treatise on the Modern Law of Contracts.1897. Volume 1. Chapter 6. Page 269.
William Wait. "Impossible Contracts". A Treatise Upon Some of the General Principles of the Law. 1885. Volume 7. Chapter 32. Page 124.
Mindy Chen-Wishart. "Physical impossibility". Contract Law. Fifth Edition. Oxford University Press. 2015. Chapter 7.3.2. Page 295.
D J Joubert. "Physical Possibility of Performance". General Principles of the Law of Contract. Juta & Co Ltd. 1987. Chapter 13. Page 124. Google
Victor Goldberg. "Impossibility and Related Excuses". Framing Contract Law: An Economic Perspective. Harvard University Press. 2006. Chapter 19. Page 333.
John Henry Schlegel, "Of Nuts, and Ships, and Sealing Wax, Suez, and Frustrating Things - The Doctrine of Impossibility of Performance" (1968 to 1969) 23 Rutgers Law Review 419
John D Wladis, "Common Law and Uncommon Events: The Development of the Doctrine of Impossibility of Performance in English Contract Law" (1986 to 1987) 75 Georgetown Law Journal 1575
"The Principle of Impossibility in Contract" (1940) 56 Law Quarterly Review 519
J Denson Smith, "Some Practical Aspects of the Doctrine of Impossibility" (1937 to 1938) 32 Illinois Law Review 672
Christopher J Bruce, "An Economic Analysis of the Impossibility Doctrine" (1982) 11 The Journal of Legal Studies 311
Richard A Posner and Andrew M Rosenfield, "Impossibility and Related Doctrines in Contract Law: An Economic Analysis" (1977) 6 The Journal of Legal Studies 83
"Impossibility of Performance" (1870) 49 The Law Times 300 (20 August 1870)
Edwin W Patterson. "Impossibility of Performance and Frustration of Purpose". Cases and Materials on Contracts II. Foundation Press. 1935. Volume 1. Chapter 3. Page 285.
George P Costigan. "Impossibility of Performance of Contracts". Cases on the Law of Contracts. Second Edition. 1932. Chapter 8. Page 700.

^ Sources also speak of a principle
^ As to impossibility of performance of contract during war, see Arnold Duncan McNair, "War-Time Impossibility of Performance of Contract", Essays and Lectures Upon Some Legal Effects of War, Cambridge, at the University Press, 1920, Chapter 5, p 78; Henry Campbell, "Impossibility of Performance", The Law of War and Contract, Humphrey Milford, Oxford University Press, 1918, chapter 5, p 263 et seq Google; K V R Townsend, "Impossibility of Performance of Contracts due to War-Time Governmental Interference" (1941) 8 Current Legal Thought 150; "Impossiblity of Performance of Contracts due to War-Time Regulations" (1918 to 1919) 32 Harvard Law Review 789; Weber, The Effect of War on Contracts, 2nd Ed, 1946, p 445 et seq; MacKinnon, Effect of War on Contract: Being an Attempted Analysis of the Doctrine of Discharge of Contract by Impossibility of Performance: With a Résumé of the Principal Cases decided in the English Courts during the Present War, 1917 Google; Trotter, The Law of Contract during War, 1914, p 57, 58 and 59 et seq Google; Trotter, The Law of Contract during and after War, 3rd Ed, 1919, p 118 et seq; Trotter, Supplement to the Law of Contract during War, 1915, pp 76, 77 and 78 et seq Google; and Coleman Philipson, "Where new circumstances would make lawful fulfilment impossible", The Effect of War on Contracts, 1909, p 78 Google.
^ As to impossibility of performance in Australia, see Bradford A Caffrey, "Impossibility: Frustration Doctrine", Guidebook to Contract Law in Australia, 4th Edition, CCH Australia, 1991, chapter 14, p 357; J W Carter and D J Harland, "Impossibility of Performance", Contract Law in Australia, Third Edition, Butterworths, 1996, p 715; "Impossibility of Performance"/"Impossibility", The Australian Digest, 2nd Edition, Law Book Company of Australasia, 1966, vol 6, divn 4 of "VII Contracts", col 394; Stewart, Swain and Fairweather, Contract Law: Principles and Context, Cambridge University Press, 2019, p 277 et seq; Yorston and Fortescue, "Impossibility of Performance", Australian Mercantile Law, 15th Ed, 1978, p 104; "Impossibility of Performance arising from an Act of State" (1916) 38 Australian Law Times 5 (22 July 1916); and Yin, Kozlina, Green, Siliquini-Cinelli, Laryea and Spagnolo, "Contracts which are impossible to perform", Contract Law: Cases and Materials, 2021 chapter 15.2.5, p 483.
^ The Australian Digest, 2nd Ed, 1966, vol 6, col 404. (1951) 45 Queensland Justice of the Peace and Local Authorities' Journal 149 and 173.
^ T Anthony Downes. "Impossibility". Textbook on Contract. Fifth Edition. 1997. Section 11.4.2.1 at p 308.
^ T Anthony Downes. Textbook on Contract. Fifth Edition. 1997. p 311.
^ 3 B.&S. 826, 122 Eng.Rep. 309 (K.B. 1863).
^ As to impossibility of performance in New Zealand, see H Jenner Wily (ed), "Impossibility of Performance", The Abridgement of New Zealand Case Law, Butterworths, Wellington, 1964, vol 3, p 238; "Impossibility of Performance", Australian and New Zealand Commentary on Halsbury's Laws of England (Fourth Edition), Butterworths, 1974, Chapter 20, para C1231 at p 75 et seq. "Contract: Impossibility of Performance" in "Case and Comment" (1950) 26 NZLJ 55 and 72 (7 and 21 March 1950); "Discharge of Contract: By Subsequent Impossibility of Performance" (1931) 7 NZLJ 286 (27 October 1931); Northey and Leys, Commercial Law in New Zealand, 5th Ed, 1974, pp 178 to 189.
^ As to supervening impossibility of performance in South Africa, see William Arthur Ramsden, Supervening Impossibility of Performance in the South African Law of Contract, Juta & Co, 1985, ISBN 0-7021-1629-7; William Arthur Ramsden, Supervening Impossibility of Performance in the South African Law of Contract, University of the Witwatersrand, 1983; William Arthur Ramsden, "Some Historical Aspects of Supervening Impossibility of Performance of Contract" (1975) 38 Tydskrif vir Hedendaagse Romeins-Hollandse Reg 153, 284 and 370; William Arthur Ramsden, "Temporary Supervening Impossibility of Performance" (1977) 94 South African Law Journal 162; Jacques du Plessis, "Supervening Impossibility of Performance – A Conceptual Conundrum and Restatement of Principles" (2022) 33 Stellenbosch Law Review 605 Sabinet; A J Kerr, "The Effect of Leases on Supervening Impossibility of Performance" (1977) 94 South African Law Journal 389; "Termination by supervening impossibility of performance", The Law of South Africa, Butterworths, 2006, vol 19, para 249 at p 170; Louis F van Huyssteen and Catherine J Maxwell, Contract Law in South Africa, 2021, paras 386 to 398; "Rendering performance impossible", Wille's Principles of South African Law, 8th Ed, Juta, 1991, p 514; J T R Gibson, "Supervening Impossibility of Performance", South African Mercantile and Company Law, 2nd Ed, Juta & Company, 1966, p 95; A J Kerr, "Breach, Supervening Impossibility and Risk" (1978) 95 South African Law Journal 16; and Martin Brassey, "The Effect of Supervening Impossibility of Performance on a Contract of Employment" [1990] Acta Juridica 22.
^ See, e.g., Transatlantic Financing Corp. v. United States, 363 F.2d 312 (D.C. Cir. 1966).

[1] Sources also speak of a principle

[2] As to impossibility of performance of contract during war, see Arnold Duncan McNair, "War-Time Impossibility of Performance of Contract", Essays and Lectures Upon Some Legal Effects of War, Cambridge, at the University Press, 1920, Chapter 5, p 78; Henry Campbell, "Impossibility of Performance", The Law of War and Contract, Humphrey Milford, Oxford University Press, 1918, chapter 5, p 263 et seq Google; K V R Townsend, "Impossibility of Performance of Contracts due to War-Time Governmental Interference" (1941) 8 Current Legal Thought 150; "Impossiblity of Performance of Contracts due to War-Time Regulations" (1918 to 1919) 32 Harvard Law Review 789; Weber, The Effect of War on Contracts, 2nd Ed, 1946, p 445 et seq; MacKinnon, Effect of War on Contract: Being an Attempted Analysis of the Doctrine of Discharge of Contract by Impossibility of Performance: With a Résumé of the Principal Cases decided in the English Courts during the Present War, 1917 Google; Trotter, The Law of Contract during War, 1914, p 57, 58 and 59 et seq Google; Trotter, The Law of Contract during and after War, 3rd Ed, 1919, p 118 et seq; Trotter, Supplement to the Law of Contract during War, 1915, pp 76, 77 and 78 et seq Google; and Coleman Philipson, "Where new circumstances would make lawful fulfilment impossible", The Effect of War on Contracts, 1909, p 78 Google.

[3] As to impossibility of performance in Australia, see Bradford A Caffrey, "Impossibility: Frustration Doctrine", Guidebook to Contract Law in Australia, 4th Edition, CCH Australia, 1991, chapter 14, p 357; J W Carter and D J Harland, "Impossibility of Performance", Contract Law in Australia, Third Edition, Butterworths, 1996, p 715; "Impossibility of Performance"/"Impossibility", The Australian Digest, 2nd Edition, Law Book Company of Australasia, 1966, vol 6, divn 4 of "VII Contracts", col 394; Stewart, Swain and Fairweather, Contract Law: Principles and Context, Cambridge University Press, 2019, p 277 et seq; Yorston and Fortescue, "Impossibility of Performance", Australian Mercantile Law, 15th Ed, 1978, p 104; "Impossibility of Performance arising from an Act of State" (1916) 38 Australian Law Times 5 (22 July 1916); and Yin, Kozlina, Green, Siliquini-Cinelli, Laryea and Spagnolo, "Contracts which are impossible to perform", Contract Law: Cases and Materials, 2021 chapter 15.2.5, p 483.

[4] The Australian Digest, 2nd Ed, 1966, vol 6, col 404. (1951) 45 Queensland Justice of the Peace and Local Authorities' Journal 149 and 173.

[5] T Anthony Downes. "Impossibility". Textbook on Contract. Fifth Edition. 1997. Section 11.4.2.1 at p 308.

[6] T Anthony Downes. Textbook on Contract. Fifth Edition. 1997. p 311.

[7] 3 B.&S. 826, 122 Eng.Rep. 309 (K.B. 1863).

[8] As to impossibility of performance in New Zealand, see H Jenner Wily (ed), "Impossibility of Performance", The Abridgement of New Zealand Case Law, Butterworths, Wellington, 1964, vol 3, p 238; "Impossibility of Performance", Australian and New Zealand Commentary on Halsbury's Laws of England (Fourth Edition), Butterworths, 1974, Chapter 20, para C1231 at p 75 et seq. "Contract: Impossibility of Performance" in "Case and Comment" (1950) 26 NZLJ 55 and 72 (7 and 21 March 1950); "Discharge of Contract: By Subsequent Impossibility of Performance" (1931) 7 NZLJ 286 (27 October 1931); Northey and Leys, Commercial Law in New Zealand, 5th Ed, 1974, pp 178 to 189.

[9] As to supervening impossibility of performance in South Africa, see William Arthur Ramsden, Supervening Impossibility of Performance in the South African Law of Contract, Juta & Co, 1985, ISBN 0-7021-1629-7; William Arthur Ramsden, Supervening Impossibility of Performance in the South African Law of Contract, University of the Witwatersrand, 1983; William Arthur Ramsden, "Some Historical Aspects of Supervening Impossibility of Performance of Contract" (1975) 38 Tydskrif vir Hedendaagse Romeins-Hollandse Reg 153, 284 and 370; William Arthur Ramsden, "Temporary Supervening Impossibility of Performance" (1977) 94 South African Law Journal 162; Jacques du Plessis, "Supervening Impossibility of Performance – A Conceptual Conundrum and Restatement of Principles" (2022) 33 Stellenbosch Law Review 605 Sabinet; A J Kerr, "The Effect of Leases on Supervening Impossibility of Performance" (1977) 94 South African Law Journal 389; "Termination by supervening impossibility of performance", The Law of South Africa, Butterworths, 2006, vol 19, para 249 at p 170; Louis F van Huyssteen and Catherine J Maxwell, Contract Law in South Africa, 2021, paras 386 to 398; "Rendering performance impossible", Wille's Principles of South African Law, 8th Ed, Juta, 1991, p 514; J T R Gibson, "Supervening Impossibility of Performance", South African Mercantile and Company Law, 2nd Ed, Juta & Company, 1966, p 95; A J Kerr, "Breach, Supervening Impossibility and Risk" (1978) 95 South African Law Journal 16; and Martin Brassey, "The Effect of Supervening Impossibility of Performance on a Contract of Employment" [1990] Acta Juridica 22.

[10] See, e.g., Transatlantic Financing Corp. v. United States, 363 F.2d 312 (D.C. Cir. 1966).

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Contract law

Formation
Capacity Offer and acceptance Meeting of the minds² Abstraction principle^4,5 Posting rule¹ Mirror image rule Invitation to treat Firm offer Consideration^1,4 Implication-in-fact Collateral contract
Defences
Misrepresentation Mistake Threats and unequal bargaining power Illegality and public policy Unconscionability Culpa in contrahendo² Force majeure Frustration of purpose Impossibility Impracticability Hardship Set-off Illusory promise¹ Statute of frauds¹ Non est factum¹ Unclean hands¹ Accord and satisfaction¹ Exculpatory clause
Interpretation
Parol evidence³ Contract of adhesion Integration clause Contra proferentem UNIDROIT Principles
Dispute resolution
Choice of law clause Forum selection clause Hague Choice of Court Convention Arbitration New York Convention UNCITRAL Model Law Mediation Singapore Mediation Convention Enforcement of foreign judgments Hague Judgments Convention
Rights of third parties
Privity of contract¹ Assignment Delegation Novation Third-party beneficiary
Breach of contract
Anticipatory repudiation Cover Exclusion clause Efficient breach Deviation Fundamental breach
Remedies
Specific performance³ Money damages Liquidated, stipulated, or penal damages³ Rescission
Quasi-contractual obligations
Promissory estoppel¹ Quantum meruit¹ Unjust enrichment Restitution Negotiorum gestio²
Duties of parties
Duty of honest contractual performance (or doctrine of abuse of rights)⁶ Duty of good faith (also implied covenant of good faith and fair dealing or duty to negotiate in good faith)⁷ Contract A and Contract B in Canadian contract law⁶
Related areas of law
Conflict of laws Commercial law
By jurisdiction
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Other law areas
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Notes
1 Specific to common law jurisdictions 2 Specific to civil and mixed law jurisdictions 3 Historically restricted in common law jurisdictions but generally accepted elsewhere; availability varies between contemporary common law jurisdictions 4 Specific to the German Bürgerliches Gesetzbuch and other civil codes based on the pandectist tradition 5 Explicitly rejected by the UNIDROIT Principles of International Commercial Contracts 6 Specific to Canadian contract law both in Québec and in the country's common law provinces 7 Specific to civil law jurisdictions, the American Uniform Commercial Code, and Canadian jurisprudence in both Québec and the common law provinces pertaining to contractual and pre-contractual negotiation
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