Consumer Credit Act 1974: Key legislation that may apply to loans exceeding £140, though informal loans between friends/family might be exempt. Sets out consumer protection framework for credit agreements.

Law of Property (Miscellaneous Provisions) Act 1989: Establishes requirements for contracts to be in writing and sets out formal requirements for valid agreements.

Limitation Act 1980: Establishes six-year limitation period for breach of contract claims, crucial for enforcement timeframes of loan agreements.

Contract Law Principles: Common law principles including offer and acceptance, consideration, intention to create legal relations, and capacity to contract.

Financial Services and Markets Act 2000: Ensures the loan agreement doesn't inadvertently fall within regulated lending activities requiring authorization.

Consumer Rights Act 2015: If applicable to the situation, ensures that terms in the agreement are fair and transparent.

Data Protection Act 2018 / UK GDPR: Governs the handling and protection of personal information that may be included in the loan agreement.