Technical specification: Transaction unique identifier and INSPIRE ID Look Up Table dataset
The Transaction unique identifier and INSPIRE ID Look Up Table dataset contains HM Land Registry Transaction unique identifier from the Price Paid dataset and INSPIRE IDs for freehold land and property registered in England and Wales.
Price Paid Data tracks property sales in England and Wales submitted to HM Land Registry for registration. Price Paid Data is based on the raw data released each month.
The amount of time between the sale of a property in England and Wales and the registration of this information with HM Land Registry varies. It typically ranges between 2 weeks and 2 months. Data for the two most recent months is therefore incomplete and does not give an indication of final monthly volumes. Occasionally the interval between sale and registration is longer than two months. The small number of sales affected cannot be updated for publication until the sales are lodged for registration
The Transaction unique identifier is a unique identifier for each published sale.
INSPIRE Index Polygons is an open-source dataset, developed to comply with the INSPIRE Directive. It contains the locations of freehold registered property in England and Wales. It is a sub-set of our Index Polygons database for all freehold land and property.
INSPIRE Index Polygons are divided into separate data files for each local authority area in England and Wales. If a polygon is on the boundary between local authorities, it will appear in both local authority data files.
The INSPIRE_ID is the unique identifier for the polygon.
Price Paid Data (PPD) and INSPIRE ID (IID) Look Up Table dataset is a list comprised of:
- Transaction unique identifier
- INSPIRE_ID
Specification scope
Inclusions and exclusions
The dataset will not provide back-dated data, only new price paid records will be included. The INSPIRE ID will be provided where that price paid record relates to a freehold title and only if an index polygon exists.
The Transaction unique identifier and INSPIRE_ID will not be published as part of HM Land Registry’s Price Paid Data Linked Data.
Limitations of data
The INSPIRE ID relates only to freehold registered property. Leasehold sales will not be included in the look up table dataset because INSPIRE Index Polygons are based on freehold registered land and property.
A property may have more than one INSPIRE ID. This can happen where the property is made up of more than one freehold title, where more than one index polygon is associated with the sale, or where an index polygon has been amended and a new INSPIRE ID has been generated under the lifecycle rules for the dataset.
Examples include:
- A house sold with an adjoining garden, garage or parking space that is held under a separate freehold title. Each freehold title may have its own INSPIRE ID.
- A property sale that includes more than one parcel of freehold land, such as a dwelling and a separate strip of access land. Each parcel may be represented by a separate index polygon.
- A freehold property where the index polygon has been amended, split or merged as part of dataset maintenance. This may result in a new INSPIRE ID being generated, even where the registered title plan extent has not changed.
Relationship to other HM Land Registry data products
The look up table dataset contains the primary identifiers from HM Land Registry’s published Price Paid Information dataset and its published INSPIRE Index Polygons service. It will enable users to join the two datasets to geolocate price paid records.
The INSPIRE_ID is the same as the POLY_ID which is published in HM Land Registry’s National Polygon Dataset.
HM Land Registry has an ambition to improve its other published datasets with the addition of the INSPIRE_ID.
Data content and structure
Table 1 - Transaction unique identifier and INSPIRE ID Look Up Table dataset: Class diagram Class diagram of the dataset which describes the content and structure
| Title Number/UPRN Look Up Table dataset |
|---|
| Transaction unique identifier |
| INSPIRE ID |
Table 2 - Transaction unique identifier and INSPIRE ID Look Up Table dataset: Table structure. Description of the data fields in the dataset
| Field name | Data type | Mandatory | Description |
|---|---|---|---|
| Transaction unique identifier | A 38-character Identifier | Yes | A unique reference, which is generated automatically, for the price paid dataset, recording each published sale |
| INSPIRE ID | 9-digit (max) Identifier | Yes | A unique number, which is generated automatically, of the published spatial object (polygon) and managed through lifecycle rules for the dataset. |
Data quality
This dataset contains identifiers only.
To understand the data quality issues of the published datasets to which they relate please see:
-
Index polygons spatial data (INSPIRE) - Use land and property data
-
National Polygon dataset - Technical specification - Use land and property data
Data capture information
This dataset contains identifiers only. These are auto generated and are unique. They are not reused.
An index polygon may be amended and a new INSPIRE_ID generated, this change does not always equate to a change to the title plan extent.
To understand the data capture information of the published datasets to which they relate please see-
-
Index polygons spatial data (INSPIRE) - Use land and property data
-
National Polygon dataset - Technical specification - Use land and property data
Data maintenance
An index polygon may go through several changes during the month, and the INSPIRE_ID may change. Only the latest version will be published.
File structure
The dataset is provided as a CSV file. The data in each file will:
-
use a comma to separate each field: ‘,’ (ASCII 44)
-
enclose all fields within double quotes: “ “ (ASCII 34)
-
use UTF-8 encoding (the way characters are coded for websites)
-
have line separation removed
File name
The file names will be structured as below:
-
pp-inspire-id-lookup_<1><2>.csv
-
<1>Month<2>Year
Example file name structure:
-
pp-inspire-id-lookup-aug-2026.txt
-
pp-inspire-id-lookup_<1><2>.txt
-
<1>Month<2>Year
Example file name structure:
- pp-inspire-id-lookup-aug-2026.txt
Queries and contact
Contact us if you need help with the dataset or have any questions:
Telephone
Telephone: 0300 006 0478
Monday to Friday, 9am to 5pm
data.services@mail.landregistry.gov.uk
We aim to respond within 2 working days
Address
Data Services Team
HM Land Registry
Rosebrae Court
Woodside Ferry Approach
Birkenhead
Merseyside
CH41 6DU