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 California, an express warranty is created when a seller makes a specific affirmation of fact, promise, or description about the services provided, which then forms part of the contract between the buyer and seller. This warranty assures the buyer of certain standards or qualities of the services. A breach of express warranty claim arises when these assurances are not met. The elements of such a claim include the sale of services, the seller's representation about the services, the representation being part of the contract, a breach of the warranty by the seller, notification of the breach by the buyer, and injury suffered by the buyer as a result. Notably, California law does not require privity of contract for a breach of express warranty claim to be valid. This means that even if the buyer was not the direct purchaser from the seller, they could still have a claim if the warranty was intended to be transferred or if the seller provided samples to a middleman with the expectation that they would reach the ultimate buyer.