Statute of Frauds 1677: Fundamental legislation requiring guarantees to be in writing and signed by the guarantor or their authorized representative. The document must contain all essential terms of the guarantee.

Contracts (Rights of Third Parties) Act 1999: Legislation governing whether and how third parties can enforce rights under the guarantee agreement.

Consumer Credit Act 1974: Applies when the guarantor is an individual and the guarantee relates to consumer credit. Imposes specific formalities and notice requirements.

Unfair Contract Terms Act 1977: Regulates the enforceability of contract terms, particularly exclusion clauses, and implements a reasonableness test for terms.

Consumer Rights Act 2015: Applies when the guarantor is acting as a consumer, imposing fairness requirements for contract terms and providing consumer protections.

Financial Services and Markets Act 2000: Relevant when the guarantee relates to regulated financial activities, imposing additional regulatory requirements.

Common Law Principles: Essential legal principles including rules of consideration, contractual interpretation, doctrine of undue influence, and rules regarding misrepresentation.