anticipatory breach

Breaking a contract before the actual time of required performance. It occurs when one person repudiates his contractual obligation before it is due, by indicating that he will not or cannot perform his contractual duties.

(OF CONTRACT) a breach committed before the arrival of the actual time of required performance. It occurs when one party by declaration repudiates his contractual obligation before it is due. The repudiation required is "a positive statement indicating that the promisor will not or cannot substantially perform his contractual duties." Restatement of Contracts §318(a); See U.C.C. §2-610. In the case of a bilateral contract, the aggrieved party may urge the repudiating party to perform without giving up the right to claim a present breach. Restatement of Contracts §320; U.C.C. §2-610(b). If, however, the repudiating party withdraws his repudiation before there has been a material change in position, the repudiation will be nullified. Restatements of Contracts §319; U.C.C. §2-611. A repudiation will justify a demand by the aggrieved party for an "assurance of performance" under U.C.C. §2-609. Where the anticipatory repudiation is by the party's conduct rather than by declaration it is called voluntary disablement. Thus, in a contract for the sale of land the seller breaches through voluntary disablement if he transfers land to a third party during the executory interval before performance is due on the first contract. In some jurisdictions no distinction is drawn between the two forms of preliminary breach.

The noun has one meaning:

Meaning #1: a breach of contract committed prior to the time of required performance
  Synonym: constructive breach