A property data api is how an investor, or the tool they use, pulls the figures a deal is read from without typing them: the sold prices in a postcode from the Land Registry, the floor area of a dwelling from the EPC register, the rent and price series from the ONS, and the area yields, advertised rents and planning data a commercial platform works from those and from the portals. Some of that data is public and free with an API of its own; some is a platform's, sold by credit or by subscription. This page sets out what an investor can pull, which source each figure comes from, and what the deal file keeps from a call so the figure read is the figure the deal was appraised on.
The public sources, and what each one answers
The Land Registry's price paid data answers what sold in a postcode, when and for how much, and is published as open data. The EPC register answers a dwelling's floor area and its energy rating, and has an open data API. The Office for National Statistics answers how rents and prices have moved by local authority, monthly, through its own API. Between them they give the sold-price half of every area reading, the floor area every comp is measured by, and the series a street's comps are sanity-checked against. None of them answers what a property rents for today; that is the portals' data, and the platforms'.
The platform sources, and what they add
A commercial property data platform joins the public sources to advertised rents and listings and sells the result by API: an area's average rent and yield by postcode district, the price per square foot, the rental demand, the planning applications nearby, the sourcing alerts. It is faster than working the public sources by hand and it is only as current as its refresh. An investor who reads a platform's yield for a district and appraises a deal on it should file the figure with its date, because the next refresh will move it, and the rent comparables sheet on this site is the property-level check no platform average replaces.
What the deal file keeps from a call
The figure, its source and the date it was read, against the deal. A rent estimate worked from three comps, an area yield read from a platform and a sold price pulled from the Land Registry are three different kinds of figure with three different shelf lives, and a deal file that keeps each with its provenance is the one an investor can defend to a partner or a lender. Yieldzo Pro keeps the deal with its comps, its area figures and their sources; it publishes no data of its own and calls no platform on the investor's behalf.
Questions people ask about property data api
Is there a free property data API in the UK?
Yes, for the public halves: the Land Registry's price paid data, the EPC register's open data API and the ONS API are free. Advertised rents and worked area yields are the platforms' data and are sold.
Does Yieldzo have a property data API?
No. Yieldzo keeps the deal file; the figures in it come from the sources the investor reads, and the record keeps each with its source and date. The guide here is what to pull and from where.
How current is property data from an API?
As current as the source's refresh: the Land Registry publishes sales monthly with a lag, the ONS monthly, the EPC register as certificates are lodged, and a platform on its own schedule. The date is part of the figure.