UK Property Valuation API - AVM and Comparables

Value a UK home, and pull the comparable evidence that supports the number.

What it collects

• Automated valuations for an address: estimated sale value with lower and upper bounds and a confidence band, estimated monthly rent with its own bounds and its own confidence band, the effective date of each, and any flags the provider raises on the valuation.
• Comparable properties around a postcode, a radius from a point, or inside a polygon, filtered on bedrooms, floor area, year built, property type, tenure, current value, last sale value, last sale date and current rent.
• Evidence per comparable: UPRN, address and coordinates, property type and sub type, bedrooms, bathrooms and receptions, new build flag, year built, tenure, floor area in square feet with whether it came from an EPC or a survey, current value and value per square foot, last recorded sale with its type, date and source, current and last rent, and EPC rating and efficiency.
• Value history on a single property lookup: every recorded sale and rent value with its type, date and source.
• Listings: the latest marketing record the provider holds against a UPRN.
• Broker records: valuations and orders already on your account, with their status.

FAQ

How do I get an automated valuation for a UK property?

Run the automated valuation mode with the address and your account ID. Write each line as the address ending in the postcode, or as "address|postcode". The row comes back with an estimated sale value, its lower and upper bounds, a confidence band, an estimated monthly rent with its own band, and any flags on the valuation.

What is a confidence band and why does it matter?

It is the provider's own grading of how reliable a given automated valuation is, and it is what separates a valuation a lender will accept from one it will not. Sale and rental valuations are graded independently, so each keeps its own band rather than sharing one.

How do I find comparable sales near a property?

Comparables search takes a postcode, a centre point with a radius in metres, or a GeoJSON polygon, and returns every property the provider holds in that area. Criteria are additive, so bedrooms, floor area, year built, type, tenure, value and rent filters all have to match at once. Set the area type to say which form your lines are in.

What units are the measurements in?

Imperial. The provider publishes floor areas in square feet and per unit values per square foot, and nothing is converted here, because a converted number with no label is worse than an unconverted one with a label. Every row carries its floor area unit and its currency explicitly.

What is the difference between current value and last value?

A current value is what the provider estimates the property is worth today. A last value is what actually happened, and it carries its own type saying whether that was an asking price, a completed sale or a valuation. They keep separate columns, because merging them would turn an aspiration into a transaction. Where the provider distinguishes a transaction outright, the last transaction value, date and source travel too.

Which credential do I need?

That depends on the product, and this API has three. The comparables and listings products use an OAuth2 client ID and secret exchanged for a bearer token. The broker product uses a gateway subscription key. The automated valuation product uses the subscription key plus a separate valuation API key exchanged for a short lived token. Most accounts hold one product, so the actor checks only the credential the chosen mode actually needs, and names the one that is missing.

Can this actor place a valuation order or spend money?

No. The broker product can place orders, which costs money and instructs work, so the route that does it is not wired up at all rather than merely unused. Every route this actor calls reads. A scheduled run cannot spend anything or start anything.

Can I check the service before using a credential?

Yes. The service status mode calls a route that needs no credential at all, so you can confirm the valuation service is reachable before committing a run to it.

What does it cost?

Pay per result. An automated valuation costs the most, a comparable slightly less, a listing and a broker record less again, and the credential-free status check is priced as low as the platform allows. Platform usage is included. Subjects the provider has no record for are never charged.

Example output

{
  "recordType": "comparable",
  "requested": "SW1A 0AA",
  "found": true,
  "uprn": "1024047438",
  "propertyType": "Terraced",
  "propertySubType": "Mid Terrace House",
  "bedrooms": 3,
  "bathrooms": 2,
  "receptions": 1,
  "yearBuilt": 1930,
  "tenure": "Freehold",
  "floorAreaSqFt": 120,
  "floorAreaSource": "EPC",
  "floorAreaUnit": "sqft",
  "saleCurrentValue": 512000,
  "saleLastValue": 465000,
  "saleLastValueType": "Sale",
  "saleLastValueDate": "2022-06-14",
  "rentCurrentValue": 2150,
  "epcRating": "C",
  "epcEfficiency": 68,
  "currency": "GBP"
}

Keyword map

UK property valuation API, automated valuation model API, AVM API UK, property comparables API, sold price comparables, rental comparables API, UPRN property lookup, EPC rating data API, house price estimate API, mortgage valuation data, surveyor comparable evidence, postcode property search API, property floor area square feet, confidence band valuation, UK residential market data.

Notes

Bring your own key. Read only by construction: no order-placing route is wired up. Token exchange, expiry and re-exchange are handled for you, including the provider's warning that the token response is cached and its stated lifetime is not reliable, so expiry is read from the token itself. Rate limiting and retries are handled too, and missing or refused credentials end the run cleanly with an explanation rather than failing it.