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 affirmation of fact or promise about the goods or services that is relied upon by the buyer as part of their agreement. This warranty does not require formal language such as 'warrant' or 'guarantee,' nor does it require the seller to have an explicit intention to create a warranty. To claim a breach of express warranty for services, a plaintiff must demonstrate that the seller sold services and made a representation about the services that was part of the basis of the bargain, that the seller breached this warranty, the plaintiff notified the seller of the breach, and that the plaintiff suffered an injury as a result. In Washington, privity is not necessary for a breach of warranty claim if the seller provides samples to a middleman or issues a transferable warranty, with the understanding that it will be passed on to the ultimate buyer. This aligns with the broader principles of contract and consumer protection law, which aim to ensure that buyers receive the quality and characteristics of services as promised by the seller.