Pret A Manger will have rolled out full ingredient labelling to all its 391 UK shops by the end of this week.
The introduction of full labelling was announced last year following an inquest into the death of Natasha Ednan-Laperouse, who suffered a fatal allergic reaction after purchasing a baguette containing sesame from a Pret outlet. A coroner described the retailers allergy labelling as "inadequate", which led it to develop a five-point allergy plan.
In the last six months labels, detailing all ingredients and the 14 EU declarable ingredients, have been introduced across its estate, alongside additional training for more than 9,000 team members.
The group's five-point plan will also see the launch of menu tablets in every shop, the removal of allergens from products and the production of quarterly food safety reports.
The inquest into Ednan-Laperouse's death also led to the introduction of legislation, which will require requiring all pre-packed food to display full ingredient and allergen labelling from October 2021.
Following her death the teenager's parents, Nadim and Tanya Ednan-Laperouse, established the Natasha Allergy Research Foundation. Commenting on the roll out, Tanya said: "Pret has shown that with a strong corporate determination to do the right thing, the food industry is capable of providing the necessary full allergen and ingredient labelling to give consumers the appropriate information and choices.
"Their research also shows 88% of the public support Natasha's Law, making it the most important priority for food retailers and customers amid the growing epidemic of allergies in the UK. Pret has taken the lead and we urge others to follow suit and prevent families in the future from suffering as we will always do."
Pano Christou, Pre's chief executive, said: "When we launched the Pret Allergy Plan, we said we would learn from the past and make meaningful changes to help customers with allergies.
"In less than a year, we have made the biggest change to Pret kitchens in our history. Software developers have created new labelling technologies. Walls have been knocked down to provide extra space in our kitchens. Electricians have been to every shop, weaving wires through some of the oldest buildings in the UK.
"It has been a real team effort. I know it's been challenging for our shops while we've made all these changes. I want to thank every team member for what they have achieved.
"Our task now is to keep delivering on the Pret Allergy Plan. Pret's commitment is absolutely clear: to make sure that every customer has the information they need to make the right choice for them."