Guarantor

The requirement that a guarantee be in writing is one of the oldest surviving rules in English law still in force. The Statute of Frauds 1677 provides, in its original language, that no action may be brought 'whereby to charge the Defendant upon any speciall promise to answere for the debt default or miscarriages of another person' unless 'the Agreement upon which such Action shall be brought or some Memorandum or Note thereof shall be in Writeing and signed by the partie to be charged therewith or some other person thereunto by him lawfully authorized.' In modern terms: a promise to answer for someone else's debt or default cannot be sued on unless it (or a memorandum of it) is in writing and signed by the guarantor.

Guarantors are most commonly encountered by tenants today. A guarantor is typically asked for where a landlord or letting agent wants extra security beyond the tenant alone — for example because the tenant is a student, is renting for the first time, or cannot otherwise show they can afford the rent. Because the underlying writing requirement comes from the 1677 Statute rather than a modern consumer-protection statute, the precise scope of what a guarantor has agreed to depends entirely on the wording of the written guarantee they signed.