A warranty deed guarantees that a seller owns the property free and clear of liens. While a special warranty deed may contain covenants of title, these covenants will usually cover only those claims arising by, through, or under the grantor.Function: A Warranty Deed transfers property ownership with guarantees, ensuring the buyer gets a clear title. A warranty deed is a legal document that a property owner signs in certain circumstances when transferring their property to a new owner. A Warranty Deed guarantees that a property's title is free from encumbrances while transferring its ownership. Both warranty deeds offer legal protections to a grantor in case there's a problem or defect with a title once it's been transferred. It's a deed to the lender who has given borrower notice of intent to file or has filed a foreclosure suit. Assignment of Beneficial Interest in a Land Trust. A warranty deed promises the seller that he or she legally owns the property. Most common references in a deed: Sole Ownership.