UK Postcode Address Lookup

Use this endpoint when you need to resolve a free-text address or place name into one or more UK postcodes — especially when the input is a partial or informal address rather than an exact postcode. Prefer this over the autocomplete endpoint when you want semantic address-to-postcode matching rather than partial postcode completion, and over the radius/coordinates endpoint when you have address text rather than lat/lng coordinates.

• No results returned if query is too vague or matches no known address
• Limit parameter ignored or clamped if outside 1-100 range
• Payment failure (402) if x402 payment header is missing or insufficient
• Query matches too many results and returns only top N by relevance
• Malformed query string returns empty result set or error
• Service unavailable on Railway hosting platform causing 5xx errors