A Practice Note discussing key considerations for counsel defending sellers against breach of warranty claims brought in sale of goods litigation governed by a US jurisdiction's version of Uniform Commercial Code (UCC) Article 2. This Note outlines common breach of warranty claims that buyers assert, including express warranty claims, implied warranty of merchantability claims, and implied warranty of fitness for a particular purpose claims, identifies the claims that certain third parties assert against sellers, and explains key defenses that sellers should prepare to assert and support.