The first Kit Kat variant to carry the Fairtrade stamp in the UK and Ireland will be the four-finger version, available from this month.
The move means African cocoa farmers from the Ivory Coast will be guaranteed fairer prices, along with being offered training and eduction.
Farmers will also get additional payments to invest in improving healthcare and schools in their communities.
Harriet Lamb, executive director of the Fairtrade Foundation, said: “Mainstream brands such as Kit Kat bring the critical mass? needed to tip the balance of trade in favour of disadvantaged cocoa farmers.” Nestlé’s move to Fairtrade is part of its global Cocoa Plan which will see £65 million invested in farmer training and supply of high-quality cocoa plants over the next 10 years.