The Food Standards Agency lists the top 14 allergens which catering establishments must be able to tell you about, in one way or another. Here is the link to the Food Standards Agency, as well as confirmation of the allergens which must be notified. They are the most common only. If you suffer from an allergy outside of the Top 14 you should still ask for the recipe to be checked for you to stay safe.
From the Food Standards Agency
In the UK, food businesses must tell you if they use any of the 14 key allergens as ingredients in the food and drink they provide.
Food businesses include restaurants, cafés and takeaways, and businesses that produce, manufacture or pre-pack food.
The 14 allergens that they need to declare are:
- cereals containing gluten – including wheat, rye, barley and oats
- crustaceans – such as prawns, crabs and lobsters
- molluscs – such as mussels and oysters
- tree nuts – including almonds, hazelnuts, walnuts, brazil nuts, cashews, pecans, pistachios and macadamia nuts
- sesame seeds
- sulphur dioxide and sulphites (if they are at a concentration of more than ten parts per million)