Incentive for fresh food on-the-go to reduce its reliance on single-use plastics.
The scheme will encourage customers to bring in their reusables by offering a 25p discount off each meal.
Over 70,000 people buy a lunch from the company’s Market Place stand which offers hot and cold food.
It is currently available in 23 stores including London Pantheon on Oxford Street, Newcastle, Norwich and Manchester.
New research by IGD (Institute of Global Distribution) said the ‘food-to-go’ sector is set to grow by 26.4% by 2024.
Paul Willgoss, director of food technology at M&S, said: “Food-to-go is a growing market so finding solutions in this space is an important part of our wider plan.
“Our priority is to reduce single-use packaging and ensure any we do use can be reused or recycled, as we work towards our 2022 target for all our packaging to be widely recyclable.”
Customers will be able to sell a range of clip storage containers from £4.
M&S has also launched a new, widely recyclable terracotta CPET tray to replace black plastic.