The a2 Milk Company is the successor of A2 Corporation Limited, a New Zealand company founded in 2000 by Dr Corran McLachlan, who was researching health effects of A1 beta-casein, and Howard Paterson, who was one of New Zealand's richest men, a significant dairy farmer, and a stakeholder in Fonterra, a dairy cooperative.

[3][4][5] Initially, A2 Corporation focused on dairy farm breeding programs to develop herds that would produce only A1 protein-free milk.

[13] In New Zealand it is illegal to make health claims about a food product without providing scientific evidence and registering the food as a medicine, and in November 2003 the New Zealand Commerce Commission advised that A2 Corporation Ltd and its licensed producers of A1 protein-free milk had agreed to amend the health claims in their promotional material following a warning from the commission.

[13][15] The company, which had been in a tenuous financial situation since beginning trading in May, went into administration in October[15] and was liquidated in November, owing farmers and processors tens of thousands of dollars.

[6][15] A NZ$1.27 million federal government grant awarded to the company in August as part of the Regional Partnerships Program was also cancelled.

A2 Australia established new contracts with the dairy farmers who had A1 protein-free herds, promising better payment terms—a week in advance instead of once per month, after shipment.

[25] In December 2012 A2 Corporation announced it would attempt to raise $20 million and list on the New Zealand Stock Exchange main board,[26] and that it would use the funds to grow its Chinese infant formula and UK milk businesses.

[28] For the 2014–2015 Financial year, The a2 Milk Company reported its Australian and New Zealand segment revenue grew by 40% vs pcp; and sales on a2 infant formula increased by 650%.

[33] A2 Corporation licensed patents filed in the 1990s by the New Zealand Dairy Board and filed its own patents on genetic tests to determine what form of beta-casein cows produce in milk and concerning potential adverse health consequences of standard milk.

[3][5][34][35] By 2012 A2 Corporation had developed a worldwide suite of intellectual property, including trademarks, trade secrets, and patents covering products, the genetic test and methods to develop A1 protein-free producing herds, as well as methods to check the protein content and fatty acid content of milk, dietary supplements with A2 beta-casein, and even therapeutic uses of A1 protein-free products.

[36] The a2 Milk Company continues to develop a portfolio of intellectual property, including trademarks and patents.

[39][40] The EFSA report, released in 2009, found that "a cause and effect relationship is not established between the dietary intake of BCM7 (beta-casomorphin-7), related peptides or their possible protein precursors and non-communicable diseases".

[42][43] In 2014 Lion, a beverage and food company that operates in Australia and New Zealand and is owned by Kirin, relaunched its Pura Milk product with a new label stating: "Naturally contains A2 protein.

[46] In August 2003, The a2 Milk Company exclusively licensed patent and trademark rights to US-based Ideasphere Incorporated (ISI) to market A1 protein-free products in North America.