A warrant is an official document giving legal permission, or a verb meaning to justify something. A warranty is a written guarantee that a product will be repaired or replaced if it is faulty. Memory hook: a warranty comes with the things you buy, and it ends in -y like a promise made to you.
The core difference
A warrant gives permission or justification, while a warranty is a guarantee attached to a product or contract.
- warrant — a legal document, or to justify: Police obtained a warrant before searching the property.
- warranty — a guarantee on a purchase: The laptop comes with a two-year warranty.
How to tell them apart
The two words are close relatives, both coming through Old French, and both carry the idea of giving assurance. The everyday split is simple: a warrant comes from a court or authority, and a warranty comes from a seller or maker.
Warrant is also a verb, meaning to justify (Her outstanding work warranted a promotion) or to guarantee. Warranty is only a noun. The mix-up tends to appear in shop and legal writing, so check whether a document permits an action or promises a repair.
