Getting started
What is a UK property data API?
A UK property data API is a programmatic interface that returns structured data about a property (type, beds, EPC band, sold-price history, ownership, environmental risk) typically keyed by UPRN, postcode or address. It abstracts away the half-dozen separate government feeds (HM Land Registry, EPC register, Ordnance Survey, Environment Agency, ONS, councils) into a single response.
How Homedata does it. One API key, with property datasets keyed to the UPRN. Find an address and its UPRN (5 tokens), then pull what you need: EPC rating, sold prices, council tax band, title, flood and other risks by UPRN, and broadband speeds by postcode. Each call is priced in tokens (1 token is 1p). No subscription required: optional monthly subscription earns bonus tokens.
Free government sources exist (the EPC register, Price Paid Data, OS Open UPRN), but they’re separate downloads, keyed differently. Homedata joins them to one property record.
What this means in practice
A mortgage onboarding flow needs to verify an applicant's declared address, fetch the EPC, retrieve last-sale price and check flood risk in under 800ms before the next form step. Building this from raw feeds means: AddressBase for matching (£15,000–£40,000/year licence), DLUHC EPC API (free but paginated), Land Registry Price Paid (free CSV bulk), Environment Agency flood data (free WMS). Engineering to keep four pipelines refreshed, joined on UPRN, served sub-second is roughly a six-month build for one engineer. A wrapped API delivers the same response in a single GET for £200–£800/month, which is why most fintechs subscribe rather than build.
Related questions
What fields should a property API return at minimum?
For most product use cases: UPRN as primary key, full structured address (organisation, sub-building, building number, building name, thoroughfare, locality, post town, postcode), property type (detached, semi, terrace, flat), built form, beds, total floor area in m², construction year band, EPC current and potential band with score and lodgement date, last sale price and date, council tax band, tenure (freehold/leasehold), and flood risk indicator. Provenance per field (which source, when refreshed) is increasingly required for regulated use.
Are property APIs subject to data protection law?
Most fields covered are about properties, not people, and sit outside UK GDPR. Owner names from Land Registry title registers, electoral roll data, and tenancy histories are personal data and require a lawful basis under UK GDPR / Data Protection Act 2018. Most commercial property APIs (including Homedata) deliberately exclude owner names and tenancy histories from the default response and require a documented lawful basis (e.g. KYC under MLR 2017) for those fields. ICO guidance on property and personal data is the canonical reference.
Building with UK property data?
See what Homedata returns for a real property, free.
Try five sample properties →