Insurance works because losses are independent of each other. Two thousand houses, each with a small chance of a fire, produce a steady and predictable total. That is what a premium is priced against.
Flood does not behave like that. When a river comes up it does not take one house in a street; it takes the street. The losses arrive together, and a pool that assumed they would not is short on exactly the day it is needed.
What that means in practice
Standard household wordings either exclude flood in the higher-risk bands or price it at a level that reads as an exclusion. It is not the insurer being awkward — it is the arithmetic the whole product rests on.
So the cover is placed separately: through the Flood Re scheme where the property qualifies, or with a specialist underwriter who prices the individual property rather than the postcode. A survey, a flood gate, a raised consumer unit and a kerb-height threshold all move the price, and none of them are visible to a comparison site.
What we need to place it
The full address with the postcode, the year of build, and the floor level of the lowest habitable room relative to the road. If it has flooded before, tell us — dates and depth. A declined proposal caused by a claim we did not know about is harder to fix than the claim was.
Ring the office before you renew. Flood placings take days, not minutes.