The hot food rule is five tests, not one
Hot takeaway food is standard-rated at 20%; most cold takeaway food is zero-rated. But the dividing line is five specific tests (gov.uk VAT Notice 709/1): whether the food was intentionally heated for consumption, heated to order, kept hot after cooking (for example in a heated cabinet), supplied in heat-retentive packaging, or advertised and marketed as a hot supply. Food that meets any one of these tests is standard-rated. Freshly baked goods that happen to be warm but satisfy none of the five tests may remain zero-rated. Edge cases in the grey zone (rotisserie chicken, toasted sandwiches, pies in a display cabinet) are where errors concentrate.