Dafen Tinplate Co Ltd v Llanelly Steel Co (1907) Ltd [1920] 2 Ch 124 is a UK company law case concerning amendment of the articles of association.

Dafen Tinplate Co Ltd was a shareholder in Llanelly Steel Co. Llanelly realised that Dafen were buying steel from an alternative source of supply, and also to buy up the company's shares (an attempt which failed). Llanelly responded by altering its articles through a special resolution to include a power to compulsorily purchase the shares of any member requested to transfer them. Dafen Tinplate argued the alteration was invalid.

The court held that the alteration was too wide to be valid. The altered article would confer too much power on the majority. It went much further than was necessary for the protection of the company. The judge seemed to be using the bona fide for the benefit of the company test in an objective sense, that is, he was judging the situation from the courts point of view.

• Allen v Gold Reefs of West Africa Ltd [1900] 1 Ch 656
• Brown v British Abrasive Wheel Co [1919] 1 Ch 290
• Sidebottom v Kershaw, Leese & Co Ltd [1920] 1 Ch 154
• Shuttleworth v Cox Bros and Co (Maidenhead) [1927] 1 Ch 154
• Southern Foundries (1926) Ltd v Shirlaw [1940] AC 701
• Greenhalgh v Arderne Cinemas Ltd [1951] Ch 286