The decision will apply to all 208 UK Pret A Manger stores. Reared in Suffolk, the chickens enjoy 20% more space than the industry standard.
According to Pret A Manger chief executive Clive Schlee: "We're always looking to do the right thing – and for us that means sourcing our ingredients within the UK wherever possible.
"We’ve been working hard with suppliers for some time to ensure sufficient higher welfare chicken is available in the UK."
Pret A Manger sells four sandwiches containing chicken – which will now use the meat sourced from higher welfare processing methods.
The company is majority-owned by European private equity firm Bridgepoint Capital.