An express warranty is any affirmation of fact or a promise made by a seller to a buyer which relates to the subject matter of the agreement and becomes a part of the basis of the bargain. It is not necessary to the creation of an express warranty that the seller use formal words such as warrant or guarantee or that the seller have a specific intention to make a warranty.

The elements of a claim for breach of express warranty for services are (1) the defendant sold services to the plaintiff; (2) the defendant made a representation to the plaintiff about the characteristics or quality of the services by affirmation of fact, by promise, or by description; (3) the representation became part of the basis of the bargain; (4) the defendant breached the warranty; (5) the plaintiff notified the defendant of the breach; and (6) the plaintiff suffered injury.

Privity (a direct relationship between the parties) is not required where the defendant furnishes samples to a middleman or makes a transferable express warranty knowing the samples or warranty will likely be submitted to the ultimate buyer.

In Washington State, an express warranty is created when a seller makes a specific promise or affirmation of fact regarding the quality or characteristics of services provided, and this promise or affirmation becomes part of the contract between the buyer and seller. To establish a breach of express warranty for services, a plaintiff must demonstrate that the seller sold services, made a representation about the services that was part of the basis of the bargain, breached this warranty, and that the plaintiff notified the seller of the breach and suffered an injury as a result. Washington law does not require privity of contract for a claim of breach of express warranty to be valid. This means that even if the buyer was not the direct purchaser from the seller, but the warranty was intended to be transferred or the seller provided samples through a middleman with the expectation that they would reach the ultimate buyer, the buyer may still have a claim for breach of express warranty.