Which document is key for regulating the affairs of a partnership?

The Partnership Deed is the essential document for regulating the affairs of a partnership. It outlines the specific terms and agreements that govern the relationship between the partners, including their roles, responsibilities, profit-sharing arrangements, and procedures for resolving disputes. This legal document establishes the framework within which the partnership operates, ensuring that all partners understand their rights and obligations.

In contrast, a Shareholders Agreement pertains to companies and governs the relationship among shareholders, while the Memorandum of Association and Articles of Association are foundational documents for corporations, detailing the company's registration, purpose, and internal rules. These options do not address the specific structure and dynamics of a partnership, making the Partnership Deed the most relevant choice for this context.