There is a substantial difference between purchasing food from a supermarket and purchasing food from a catering service. Most foods from a supermarket are classed as zero-rate (NOT exempt from VAT – a major difference), exceptions – from memory- include chocolate and non-essential items which are standard rated). Cold foods from a stall/sandwich shop are zero-rated. If you eat on their premises (which includes a specified area outside the shop) then VAT will be charged as it moves from providing a cold sandwich to providing a service of allowing you somewhere to eat. Also if you hire a company to provide catering, then their whole service (including any food) is standard rated as they are providing a service. If the food for take away is hot then it carries VAT at the standard rate. This is not a simple subject unfortunately and there are plenty of Grey areas and loop holes.