Also known as: impracticability defense · impracticability · commercial impracticability · UCC 2-615
Written by attorneys · grounded in primary & secondary sources — see below
A contractual defense that excuses a party's nonperformance when a supervening event renders performance impracticable without the party's fault and the nonoccurrence of the event was a basic assumption of the contract. The defense discharges the duty to perform unless the parties agreed otherwise or the impracticability is only temporary and does not materially increase the burden after it ends. It applies only to the duty of performance and does not affect claims for breach that have already arisen.
Dominic Drake contracted with Dominion Capital to haul goods daily through a single mountain pass for five years. An unanticipated avalanche led to an indefinite official closure. Drake stopped performance after forty-five days because alternate routes tripled fuel costs. The supervening closure discharged Drake's duty under the contract.
Deborah Dunn contracted to manufacture goods whose production unavoidably invaded Dylan Duffy's adjacent land with emissions. Preventing the invasion proved impracticable despite reasonable efforts. The supervening impracticability discharged Deborah's duty under the contract.
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Daphne Doyle agreed to supply parts to Delta Dynamics for six months. A fire closed Doyle's plant for two weeks. Performance resumed afterward without material increase in burden, so the temporary impracticability merely suspended Doyle's duty during the closure.
Diego Duarte repudiated a supply contract with Duarte Shipping. Later investigation revealed that a supervening regulatory ban would have made Duarte's performance impossible before any nonperformance. The duty to pay damages for the repudiation was discharged.
Dustin Donovan was named beneficiary of a contract between two companies. A supervening event rendered the promisor's performance impracticable. Donovan's right to enforce the contract was discharged to the same extent.
Eastern Air Lines and Gulf Oil entered a long-term jet fuel supply contract at a fixed price. World events sharply raised Gulf's costs. Performance remained possible though more expensive, so the defense of impracticability did not excuse Gulf's duty.
The party must show that a supervening event made performance impracticable without its fault and that the nonoccurrence of the event was a basic assumption of the contract. The defense yields to contrary agreement by the parties.
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Temporary impracticability suspends the duty only while the condition exists. It discharges the duty only if resuming performance afterward would be materially more burdensome than originally contemplated.
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A party's duty to pay damages for repudiation is discharged if later facts show the repudiated duty would have been excused by impracticability before any nonperformance occurred.
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If impracticability causes the contract to cease being binding, the beneficiary's rights are discharged or modified to the same extent.
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…method of performance, compare Annot., 84 A.L.R.2d 12, 19 (1962), there is nothing necessarily inconsistent in claiming commercial impracticability for the method of performance actually adopted; the concept of impracticability assumes performance was physically possible. Moreover, a rule making nonperformance a condition precedent to…