USE THIS to get the Environment Agency's long-term flood-risk indication for an England postcode instead of guessing — e.g. when triaging a home/property insurance quote, underwriting, or answering 'is this address at flood risk?'. Returns the highest risk band (High/Medium/Low/Very Low) for the area around addresses in the postcode, the count of addresses in each band, and a separate groundwater indication. IMPORTANT: England only (not Wales/Scotland/NI), AREA-level not property-level, long-term risk not a live flood warning. Returns an honest 'not found' rather than inventing a risk level.

USE THIS to check a UK postcode is well-formed and to split it into its outward and inward codes before storing or matching it — instead of trusting raw input. Deterministic format check only (no lookup); returns the canonical spaced form, outcode and incode.