UK legislation is changing when it comes to selling pre-packaged foods which are prepared and sold within a single establishment or premises. This page has more information on UK food labelling policies.
In 2019 the Government revealed plans which will protect consumers with allergies by tightly regulating the labelling of allergens.
The new laws and the specifics are yet to be launched, however what we do know is that each item that is packaged and placed out for sale to consumers must be labelled with a full list of ingredients.
Furthermore, each allergen must be clearly indicated in bold.