How we calculate sold house prices

Where the sales come from

Every sold price is from HM Land Registry's Price Paid Data, the register of property sales in England and Wales since January 1995. We import the full dataset and each monthly update as HM Land Registry publishes them (around the 20th working day of the following month) and re-run every figure on the site.

Scotland and Northern Ireland are not in this dataset. Registers of Scotland and Land & Property Services do not publish an open transaction record, so our pages for Scottish places show the official UK House Price Index figure and homes for sale rather than individual sales.

Which sales count

Averages use "category A" sales only — standard sales of houses and flats at full market value. HM Land Registry's "category B" transactions (buy-to-let, repossessions, transfers under a power of sale, corporate purchases and similar) are listed on street pages, flagged, but never averaged. Property type "other" (commercial, land, mixed use) is never shown.

Prices under £10,000 (or under £20,000 from 2010) and over £50 million are excluded. Where a freehold and a leasehold record share an address and a completion date we keep one. Blocks of five or more sales on the same day at the same price in one postcode district are treated as portfolio transfers and left out.

Medians, windows and the registration lag

Every "average" is a median: half of sales were above it, half below. Means are only quoted on request pages because a handful of very expensive sales can move them a long way.

Sales are dated by completion, not by registration, and registration lags completion by anything from a few weeks to nine months. Our headline windows therefore end two months before the newest sale in the data, sales counts are always "registered so far", and we never print a year-on-year change in the number of sales. The most recent months in the trend charts are hatched as provisional.

Year-on-year change compares the median of the latest 12-month window with the 12 months before it, only when both windows hold at least 30 sales and the change is within ±40%; larger swings almost always mean the mix of homes sold changed, not their value.

Price per square foot

Floor areas come from Energy Performance Certificates, matched to each sale by address within the same postcode (the latest certificate for the dwelling). Around nine in ten sales can be matched. Price per square foot is the sale price divided by the certificate's total floor area, excluding implausible results (below £50 or above £10,000 per square foot, or areas outside 15–1,000 m²). We quote the median with the interquartile range and always say how many sales were matched.

A certificate can predate an extension, so an individual figure can be wrong; the medians are robust to that.

How areas are defined

Towns are HM Land Registry post towns, qualified by postcode area where the same name appears in different places. London boroughs are the ONS local-authority boundaries. Suburbs and districts are the postcodes closer to that place's centre than to any neighbouring place's centre within the same local authority. Counties are ceremonial counties assembled from the local-authority names HM Land Registry records. Every page prints its own definition.

Because portals and the ONS draw different boundaries and use different windows and methods, their figures will differ from ours. Each page links the official UK House Price Index figure for its local authority alongside our median.

When pages are published

An area gets a full page when it has at least 30 sales in the headline window and 100 in five years. Places with fewer sales show five-year figures and are kept out of search engines. Street pages need at least three recorded sales.

Corrections and removals

We display public records and do not alter them. HM Land Registry handles corrections to the register; we re-import monthly. Verified owners can ask us to hide their sale from public address lists — it stays in the aggregates. See the data requests page.