This chapter focuses on the company constitution, essentially the articles of association. The chapter covers the need for articles (including the adoption of the model articles), amending the articles, interpreting the articles, enforcing the articles, and shareholders’ agreements. It particularly considers the extent to which shareholders can alter the articles and the common law limits to the power to do so. Altering the articles to allow for the compulsory transfer of members’ interests is also considered. Interpreting the articles and enforcing the statutory contract created is addressed. Shareholder agreements can provide better protection for shareholders and the chapter considers how they can supplement the company's articles.