An implied warranty is a common law term used in United States contract law to describe certain assurances that are presumed to be made with the sale of goods or realty because of the circumstances of the sale. These are characterized as a warranty irrespective of whether the seller has expressly promised them, or put them in writing. These include an implied warranty of fitness for a particular purpose, an implied warranty of merchantability for goods, and an implied warranty of habitability for a home.

Implied warranty of merchantability

An implied warranty of merchantability is a warrantly implied by law that if a merchant (meaning someone who makes an occupation of selling things) sells something, that merchant is guaranteeing that the goods are reasonably fit for the general purpose for which they are sold.

Implied warranty of fitness for a particular purpose

An implied warranty of fitness for a particular purpose, sometimes referred to simply as a warranty of fitness, is a warrantly implied by law that if a seller knows or has reason to know of a particular purpose for which some item is being purchased by the buyer, the seller is guaranteeing that the item is fit for that particular purpose. This differs from a warranty of merchantability in two ways:

• First, the warranty of fitness applies to all sellers, not just professional merchants; and
• Second, the warranty of fitness requires the seller to know or have reason to know of a specific purpose to which the property sold is going to be put.

For example, if Joey buys four end-tables from Susan (a non-merchant) and then uses them to prop up his car while he works on the muffler, Susan is not liable for any injury that occurs to Joey - unless Joey told Susan that he was buying the end-tables for that purpose.

Implied warranty of habitability

An implied warranty of habitability a warrantly implied by law that by leasing a residential property, the lessor is promising that it is suitable to be lived in, and will remain so for the duration of the lease.