Excuse of Performance: Impossibility, Impracticability, and Frustration
Key Takeaways
- IMPOSSIBILITY discharges a duty when performance has become OBJECTIVELY impossible ('no one could perform') due to an event whose non-occurrence was a basic assumption — classic triggers are death/incapacity of a party essential to PERSONAL-SERVICE performance, destruction of the specific subject matter, and supervening illegality.
- IMPRACTICABILITY (UCC 2-615; Restatement 261) excuses performance made EXTREMELY and unreasonably difficult or expensive by an unforeseen event whose non-occurrence was a basic assumption, provided the party did not assume the risk and is not at fault; mere increased cost or a market shift is usually NOT enough.
- FRUSTRATION OF PURPOSE discharges a duty when an unforeseen event destroys the PURPOSE that was the basis of the contract, known to both parties — performance is still possible but pointless (the Coronation cases); the frustrated party still must show the purpose was the foundation of the deal.
- Under UCC 2-615, when a seller's capacity is partially impaired (e.g., a key supplier fails) the seller must ALLOCATE production fairly among customers and notify buyers; buyers may then accept the reduced quota or terminate as to the deficiency (2-616).
- RISK ALLOCATION controls: force-majeure clauses, the assumption of risk by trade usage or course of dealing, and foreseeability all defeat these excuses; on discharge, the parties are relieved going forward and restitution reverses benefits already conferred.
Impossibility
Impossibility discharges contractual duties when, after formation, performance becomes objectively impossible — meaning the thing literally cannot be done by anyone, not merely that THIS party cannot do it (subjective inability, like lack of funds, is no excuse). The triggering event must arise from circumstances whose non-occurrence was a basic assumption of the contract, and the party seeking discharge must not have caused the impossibility or assumed its risk.
Three classic categories:
- Death or incapacity of a person necessary for performance — but only where the contract calls for that person's UNIQUE personal services (an opera singer, a portrait painter). A duty to deliver fungible goods is not discharged by the obligor's death; the estate performs.
- Destruction of the specific subject matter essential to performance, without fault (Taylor v. Caldwell — a music hall burned down before the concert). The thing destroyed must be the one the contract identified.
- Supervening illegality — a change in law makes performance unlawful after the contract was formed.
The doctrine is temporal: temporary impossibility merely suspends the duty during the impossibility and for a reasonable time after, unless performance would then be materially more burdensome. Partial impossibility discharges only the impossible part. The rule applies to both common-law and goods contracts (the UCC channels it through impracticability).
Impracticability: UCC 2-615 and Restatement 261
Modern law extends impossibility to commercial impracticability. Under UCC 2-615 (and Restatement (Second) 261), a party is excused when performance is made impracticable — extremely and unreasonably difficult, expensive, or dangerous — by the occurrence of an event whose non-occurrence was a basic assumption of the contract, AND the party seeking excuse did NOT assume the risk and is NOT at fault.
The bar is high. Courts deny the excuse for:
- Mere increased cost or a swing in market price — these are the ordinary risks of contracting (a tenfold cost increase might qualify; a 50% increase usually will not).
- Foreseeable events the party could have provided against.
- Risks the contract or trade usage allocated to the party (a fixed-price contract allocates price risk to the seller).
Examples that may qualify: an embargo or war closing the only feasible shipping route at extraordinary cost, a crop-specific drought destroying the source the contract assumed, or destruction of the seller's sole plant without fault. The party must notify the buyer.
Impossibility vs. Impracticability vs. Frustration
| Doctrine | What happens to performance | Core question |
|---|---|---|
| Impossibility | Performance literally cannot be done | Has performance become objectively impossible? |
| Impracticability | Performance possible but extreme/unreasonable burden | Did an unforeseen basic-assumption event make it commercially senseless to require performance? |
| Frustration | Performance still possible and feasible, but pointless | Has the principal purpose been destroyed? |
Frustration of Purpose and Allocation
Frustration of purpose discharges a duty when, after formation, a supervening event destroys the principal purpose of the contract, where that purpose was a basic assumption known to both parties, performance is still possible but has lost essentially all its value to the frustrated party, and that party did not assume the risk. The doctrine comes from the Coronation cases (Krell v. Henry): a flat was rented at a premium SPECIFICALLY to view the king's coronation procession; when the coronation was postponed, the renter's purpose was frustrated even though he could still occupy the flat.
Frustration requires that BOTH parties understood the special purpose; if only one party privately intended a use, its loss does not frustrate the contract. A mere reduction in profitability or a less-advantageous deal is not frustration.
UCC allocation and notice (2-615, 2-616): When a seller's ability to perform is only PARTIALLY impaired (a key raw-material supplier fails), the seller may not simply walk away — it must allocate production and deliveries among its customers in a fair and reasonable manner (it may include regular customers not under contract and its own requirements). The seller must notify buyers of the delay or quota. Under 2-616, a buyer receiving such notice may either terminate as to the affected deliveries or agree to take its available quota in substitution.
Effect of discharge: Excuse relieves both parties of further performance going forward. Benefits already conferred are reversed through restitution to prevent unjust enrichment (e.g., recovering a prepaid deposit, less the value of any performance received). A force-majeure clause can expand or contract these doctrines by allocating specified risks expressly.
Foreseeability is the silent gatekeeper. All three doctrines require that the supervening event's non-occurrence was a BASIC ASSUMPTION of the contract — which means the event must have been UNFORESEEN (or at least not a risk the contract implicitly allocated). If the parties could have anticipated the event and provided for it, the party seeking excuse usually bears the risk. This is why long-term supply contracts rarely escape on impracticability: price volatility and supply disruption are exactly what such contracts are written to allocate. Always ask three questions: (1) Was the event truly unforeseeable?
(2) Did the contract, trade usage, or course of dealing allocate this risk? (3) Was the party seeking excuse free of fault in causing the event? A 'no' to (1) or (3), or a 'yes' to (2), defeats the excuse.
A manufacturer signs a fixed-price contract to supply steel for one year. Six months in, the world price of steel triples due to an unforeseen but not catastrophic market shift, and the manufacturer claims it is excused by commercial impracticability. Will the excuse succeed?
A spectator rents a balcony at a high premium for the sole, mutually known purpose of watching a parade. The parade is cancelled by the government. The balcony is still fully usable. Which doctrine best excuses the renter's duty to pay?