As regards treaties and conventions, article 60, paragraph 3, of the Vienna Convention on the Law of Treaties states: "A material breach of a treaty, for the purposes of this article, consists in:

(a) a repudiation of the treaty not sanctioned by the present Convention; or

(b) the violation of a provision essential to the accomplishment of the object or purpose of the treaty."

Article 60, paragraph 2 discusses the consequences of such a breach: "A material breach of a multilateral treaty by one of the parties entitles:

(a) the other parties by unanimous agreement to suspend the operation of the treaty in whole or in part or to terminate it either:

(i) in the relations between themselves and the defaulting State, or

(ii) as between all the parties;

(b) a party specially affected by the breach to invoke it as a ground for suspending the operation of the treaty in whole or in part in the relations between itself and the defaulting State;

(c) any party other than the defaulting State to invoke the breach as a ground for suspending the operation of the treaty in whole or in part with respect to itself if the treaty is of such a character that a material breach of its provisions by one party radically changes the position of every party with respect to the further performance of its obligations under the treaty."

In Anglo-Saxon contract law a material breach usually excuses the aggreived party from further performance and affords it the right to sue for damages. (An immaterial breach, or partial breach, is one that is less significant than a material one. It gives the aggrieved party a right to damages, but does not usually excuse that party from performance.)

The term "material breach" was a crucial component of S/RES/1441 (2002) on Iraq, in which the Council decided [para. 1] "that Iraq has been and remains in material breach of its obligations under relevant resolutions"; and [para. 4] "that false statements or omissions in the declarations submitted by Iraq pursuant to this resolution and failure by Iraq at any time to comply with, and cooperate fully in the implementation of, this resolution shall constitute a further material breach of Iraq’s obligations".

Variante (NPT): material non-compliance