Contract Law (Chapter 53A): Primary legislation governing contract formation, terms and conditions, and capacity of parties in Singapore. Essential for ensuring the authorization letter meets basic contractual requirements.

Personal Data Protection Act 2012 (PDPA): Regulates the collection, use, and disclosure of personal data. Relevant for handling personal information of both authorizer and authorized person, including consent requirements and data protection obligations.

Electronic Transactions Act: Governs electronic transactions and signatures in Singapore. Important if the authorization letter is to be executed electronically, covering requirements for e-signatures and validity of electronic documents.

Stamp Duties Act: Determines whether stamp duty applies to the authorization letter and outlines proper execution requirements for legal documents in Singapore.

Powers of Attorney Act: Relevant if the authorization could be considered a power of attorney, outlining formal requirements and scope of delegated authority.

Evidence Act: Specifies requirements for document admissibility as evidence and authentication requirements in legal proceedings.