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Code-Point with Polygons

Code-Point with Polygons is a dataset that contains the notional area of postcode units, designed to allow customers to display and analyse any data collected at the postcode level. Polygons within this product are derived from georeferenced Royal Mail Postal Address File (PAF) delivery addresses and processed using a Thiessen process to create mathematically consistent boundaries between distinct postcode groups as a notional boundary set.

This product is updated quarterly

Visualise postcode extents

Codepoint with Polygons provides notional extents for every postcode unit in GB for easy visualisation and analysis at a national scale.

Vertical Street polygons

Vertical street polygons allow easy identification of multiple postcodes within the same building.

Precise polygon data

Postcode polygons created using the addresses we can locate the most precisely creating high confidence in the accuracy of the polygon data.

Manage your risks better

Display postcode boundaries on a map, then add contours and your own claims data. This is a great way to identify low-lying postcodes, so you can quote for insurance at a price that reflects higher flood risks.

Access: Download
Data theme: Administrative and Statistical Units
Data structure: Vector - Polygons
Coverage: Great Britain
Scale: 1:1 250 to 1:10 000
Format: MapInfo MID/MIF, MapInfo TAB
Ordering area: All of Great Britain
Publication months: January, April, July, October
OS Data Hub plan: Public Sector Plan, Premium Plan, Energy & Infrastructure Plan

Code-Point accuracy and resolution

Code-Point is created by taking the average of the coordinates of all the individual addresses in a postcode (provided we have any of sufficient quality), then snapping to the nearest of those addresses. Code-Point then delivers the coordinates of that address, as representative of the whole postcode, to a resolution of 1 metre.

The accuracy of a Code-Point Open record could be expressed as, that the coordinated position will always be within the notional geographical extent of the postcode. The accuracy of each postcode unit coordinate pair is defined by the positional quality indicator (PQI) which provides a quality statement of a Code-Point record.

How to get this product

Access to this product is free for PSGA members. Find out if you are a PSGA member or try out a sample of Code-Point with Polygons data by accessing the product page here with links to all of the relevant resources. Alternatively, you can try out the full product by applying for a Data Exploration license.

Code-Point with Polygons Overview

This overview introduces Code-Point with Polygon, giving context for all users – highlighting key features, providing examples of uses, and listing details such as file sizes, supply formats, etc.

Code-Point with Polygons is a dataset that contains the notional area of postcode units, allowing customers to display and analyse any data collected at the postcode level.

The polygons within the product are derived from georeferenced Royal Mail Postal Address File (PAF) delivery addresses. A process is undertaken to create a set of polygons around individual address records within a postcode. This is called a Thiessen process and the polygons are the result of a mathematical computation that creates polygons from point data. In this way, mathematically consistent boundaries are created between distinct postcode groups, creating this notional boundary set.

Postcode unit boundaries are, by definition, only the delivery point or collection of delivery points that constitutes the postcode units. The boundary is therefore a notional one, the position of which is arbitrary. What has been created, however, is a set of boundaries that follows a consistent logic and portrays the notional footprint of each postcode unit. The boundary encloses every delivery address for which positional data of sufficient quality is available, and which follow major physical features that could reasonably be regarded as part of the postcode boundary.

Key features of the product

The key features of the Code-Point with Polygons product are as follows:

A set of 120 postal-area-based files that provide a set of boundaries for the postcode units in Great Britain for shapefile, TAB and MID/MIF supply formats. For vector tiles and GeoPackage supply formats, a single national file is provided.
Vertical_streets: A list of polygons for locations that contain more than one postcode, for example, office blocks and flats.
Corresponding Code-Point information providing the number of delivery addresses and the health and administrative area codes related to each postcode.

Uses of Code-Point with Polygons

The quality of this polygon creation allows the polygons to be used for a wide range of applications. This will include analysis of geographically based information or statistics by postcode, and the pictorial display of information that has been analysed or sorted by postcode.

Product details

Postcodes

There are two main components of a postcode:

The outward code (also called outcode): The first two to four characters of the postcode constitutes the postcode area and the postcode district. It is the part of the postcode that enables mail to be sent from the accepting office to the correct area for delivery.
The inward code (also called incode): The last three characters of the postcode constitutes the postcode sector and the postcode unit. It is used to sort mail at the local delivery office.

For example:

Outward

Inward

When used in an address, the incode should be separated from the outcode by a single space. The following table is a list of the valid formats of postcodes (an A indicates an alphabetic character; an N indicates a numeric character):

Outcode

Incode

Example postcode

Postcode polygon geometry

Postcode polygons are produced by the tessellation of georeferenced PAF coordinates for individual Royal Mail delivery addresses. Only addresses having a positional quality value indicating the location is within a building are used to create the polygons file. Postcodes of addresses of lower quality will be included in the discard files.

Due to the nature of postcode geography, the polygons representing some postcode units are unavoidably split. Every effort has been made to ensure the absolute minimum of postcodes is represented by multiple polygons. These split polygons representing a single postcode remain a single object with one set of attributes.

Each polygon is assigned a unique identifier. The identifier will be a 16-digit series. These identifiers are not reused should a polygon be deleted.

The polygon dataset contains non-overlapping polygon coverage of Great Britain, originally constrained by the extent of realm (EOR) coastline from Ordnance Survey’s Boundary-Line data and postcode polygons. Should any addresses fall outside the constraining datasets, the postcodes should be included in the discard files.

For Shapefile, TAB and MID / MIF supply formats the data is divided into 120 postcode area files, each file named with a one or two letter postcode area code, and for vector tiles and GeoPackage supply formats, the data is provided as one national file.

Vertical streets

Postcodes that are vertically stacked, that is, two or more postcodes within a single building that are represented by a single large-scale building seed. In these situations, a single square polygon represents all the postcodes attributed to the single building seed. These polygons have a special series of identifiers, all commencing with the letter V.

A separate vertical streets lookup table is provided with the polygons and lists the postcodes with the 20-digit unique identifier that are represented by each special polygon. Where these distinctive polygons are crowded closely together, they are reduced in size to prevent overlaps hiding some of the polygons.

Data capture

The polygon set contains a polygon for every postcode in England, Scotland and Wales that is contained in Royal Mail’s PAF product, with the following exceptions:

Postcodes for which there is no location data of sufficient quality.
Postcodes for which there is no data that lies within the extent of the realm coastline.
Postcodes that relate to PO Boxes.
GeoPlace geocode the PAF data from Royal Mail, using source coordinates from Local Authorities in England, Wales and Scotland and Ordnance Survey. GeoPlace then provide the georeferenced PAF data to Ordnance Survey.

Coordinate reference systems

BNG uses the OSGB36 geodetic datum and a single Transverse Mercator projection for the whole of Great Britain. Positions on this projection are described using Easting and Northing coordinates in units of metres. The BNG is a horizontal spatial reference system only; it does not specify a vertical (height) reference system.

Currency

Updates are supplied quarterly in January, April, July and October, and are a complete resupply of the national dataset.

Each edition of Code-Point with Polygons will have a version number showing the release month for the year (for example, April) followed by the release year (for example, 2022).

The version for each quarterly release will be in this format:

April_2022
July_2022
October_2022
January_2023

The Code-Point data packaged alongside the postcode polygon data will be the data from the most recent Code-Point product release. Typically, this is the Code-Point release from two months prior. For example, the October 2022 release of Code-Point with Polygons will be supplied alongside the August 2022 release of Code-Point.

Product supply

Supply format and media

Code-Point with Polygons is available in the following formats:

Shapefile
MapInfo MID / MIF
MapInfo TAB file
Vector tiles (MBTiles)
GeoPackage (GPKG)

Code-Point with Polygons is supplied as a zip file in the Data folder, either downloaded from the OS Data Hub or on a DVD (TAB, Shapefile and MID / MIF formats only). The Code-Point polygon files contain substantial amounts of information, which in shapefile, MID / MIF, TAB and vector tiles formats necessitate that file compression be used.

The vector tile and GeoPackage formats of the product are not available as a DVD supply option.

Coverage and file sizes

The polygon data coverage is Great Britain. The shapefile, TAB and MID / MIF formats are split into 120 files where each file represents the notional geometry for a postcode area. The vector tiles and GeoPackage formats are supplied as one national file.

File sizes for Great Britain are approximately:

Shapefile: 610 MB
TAB: 524 MB
MID / MIF: 564 MB
Vector tiles (MBTiles): 457 MB
GeoPackage (GPKG): 708 MB

The following two CSV text files accompany the polygon data:

Vertical_streets: A list of polygons, identified by a serial number that is prefixed by the letter V, which contain more than one postcode. This situation can occur in, for example, a block of flats where there is more than one postcode within a single building.
Discard_files: A list of the postcodes for which polygons have not been included because there is no data of sufficient quality to use in the polygon creation, or because their constituent addresses lie outside the extent of the realm (coastline). The discard file also contains a list of PO Box postcodes as none of these will have been used in the creation of the polygon set.

The associated Code-Point coverage is for the United Kingdom, provided as 121 comma-separated value (CSV) files, as it includes Northern Ireland postcodes. Polygons are not provided for Northern Ireland postcodes. Code-Point contains georeferenced postcode unit data, with associated metadata such as address counts and quality indicators. It also provides the health and administrative area codes related to each postcode.

The following text files that are associated with the Code-Point data provide:

The full-text equivalents of the administrative area codes.
The number of postcode units in each postcode area.

Code-Point with Polygons Getting Started Guide

This getting started guide provides instructions for using Code-Point with Polygons in different software applications. Users with limited technical knowledge will be able to follow this guide.

Code-Point with Polygons is a dataset that contains the notional area of postcode units, allowing customers to display and analyse any data collected at the postcode level.

Postcode unit boundaries are, by definition, only the delivery point or collection of delivery points that constitutes the postcode units. The boundary is therefore a notional one, the position of which is arbitrary. What has been created, however, is a set of boundaries that follows a consistent logic and portrays the notional footprint of each postcode unit. The boundary encloses every delivery address for which positional data of sufficient quality is available, and which follows major physical features that could reasonably be regarded as part of the postcode boundary.

This getting started guide focuses on using the product in Shapefile, TAB and MID / MIF formats. For guidance on using the product in vector tiles or GeoPackage formats please see the following getting started guides:

Using the vertical street lookup

MapInfo

MapInfo software enables a separate browser to be viewed that contains all the postcodes related to a vertical street.

To view the vertical street lookup in MapInfo, open the file in a browser.

To join the Code_Point Polygons table and the vstreet_lookup table follow these instructions:

Save copies of the main Code-Point Polygons and Vertical Street Lookup tables to work on; for example, CP_Polys.TAB and vstreet_lookup.TAB. Open the new copies of the datasets in MapInfo.
Create a new column, of Character (8) type, in the Code-Point Polygons table (CP_Polys.TAB) as column 2. Give it a meaningful name; for example.
VS_Postcode (go to Table > Maintenance > Table Structure).
Save the table.

Create geometry for the Vertical Street Lookup table (vstreet_lookup.TAB) by joining it to the main Code-Point Polygons table using the following SQL Select query:

SELECT CP_Polys.POSTCODE, vstreet_lookup.COL1, CP_Polys.UPRN, CP_Polys.AREA_CP, CP_Polys.obj FROM CP_Polys INNER JOIN vstreet_lookup ON CP_Polys.POSTCODE = vstreet_lookup.COL2;

Save a copy of the results of the selection as PC_VS_join.TAB.
Open the table.

Delete the vertical streets from the main Code-Point Polygons table, CP_Polys.TAB – use Query > Select… to search for postcode 'Like “v%” and delete:

Save, then pack the Code-Point Polygons table.

Go into Table > Maintenance > Pack Table and select Pack Both Types of Data.

Append the Postcode – Vertical Street join table, PC_VS_join, to the main Code-Point Polygons table, CP_Polys, to create a list of all postcodes including vertical streets (Table > Append Rows to Table).
Save the CP_Polys table.

If you browse the CP_Polys table now, the rows with a ‘standard’ postcode will have a blank in the second field (VS_Postcode), but the rows that have a vertical street postcode in the Postcode (first) column should have a ‘standard’ postcode in the second field.

ESRI

ESRI software enables a relationship to be created between two tables. By relating the postcode area and vertical street lookup, it is possible to identify the postcodes related to a vertical street by using the Identify tool.

Load the postcode area Shapefile and relevant vertical street lookup file into ESRI ArcMap.

NOTE: it may be necessary to remove the underscores in the vertical street file name for it to load successfully into ArcMap.

Right-click on the postcode area Shapefile, go to Joins and Relates and click on Relate.

The Relate window will open.

In option 1, click on the drop-down arrow and select ‘POSTCODE’.

In option 2, select the vertical street lookup file.

In option 3, select Col2 or the vertical street ID column (this depends how you have named your columns).

In option 4, choose a suitable name for the relate.

Click OK.

When using the Identify tool in ESRI ArcMap, click on a vertical street polygon and expand the + signs on the left to see all the postcodes related to that vertical street polygon.

PostGIS and QGIS

PostGIS and QGIS can be used in conjunction with each other to create a vertical street lookup table, which can be visualised and interrogated within the QGIS GIS environment alongside the spatially enabled Code-Point postcode area polygons.

PostGIS steps

Load both the postcode area polygons and vertical street text file into PostGIS in their own separate tables within the same schema.
You will now create a new vertical street lookup table within PostGIS that contains the geometry of the vertical streets, obtained from the postcode area polygons table. Because you will be using the postcode columns from both the postcode area polygons table and the vertical street table you must ensure the postcode columns are named differently. The following SQL can be used to alter the name of the postcode column within the vertical street table:

alter table verticalstreets rename column postcode to vs_postcode;

Once you have ensured that all the columns in the two tables are named differently you can run the following script, which will create a new table which will contain all the vertical streets and their associated geometry:

create table vertical_street_lookup as select * from codepoint c, verticalstreets v where c.postcode=v.v_id;

This SQL creates a table by joining the vertical street IDs in the vertical street table with those IDs held in the postcode column of the postcode area polygons. The resulting table will effectively hold two columns of identical vertical street IDs, one from the vertical street table itself and one from the postcode column of the postcode area polygons table. The following script can be used to drop one of these columns, removing this duplicated information:

alter table vertical_street_lookup drop column postcode;

The postcode area polygons table can be altered to create a flag that alerts you to which postcodes form part of a vertical street. If you do not wish to create this flag, move onto the QGIS steps.
First you need to create a Boolean column within the postcode area polygons table to hold this information. Execute the following SQL to achieve this:

alter table codepoint add column vs boolean;

This column then can be updated with a value of ‘true’ where a postcode in the postcode area polygons table forms part of a vertical street. The following SQL can be used to do this:

update codepoint

set vs = 'True' where postcode in (select c.postcode from vertical_street_lookup v, codepoint c where v.vs_postcode=c.postcode or c.postcode=v.v_id);

QGIS steps

Once you have created a new vertical street lookup table with a geometry column as outlined in the steps above, this can be visualised within QGIS using the following steps:

Connect to PostGIS by selecting the Add PostGIS Layers button.
This will bring up an Add PostGIS Table(s) dialogue box. If you have not already connected to your PostGIS database select the New option and fill in the Create New PostGIS Connection dialogue box.
Once you have added your connection details, select the Test Connect option to ensure the details are correct. When your connection is successful, click OK to save the connection, it should then appear in the connections drop-down. Select Connect and the schemas within your database will be populated. Expand the schema you are using and select both the postcode area polygons table and the vertical street lookup table you have created. Add them to QGIS by selecting Add at the bottom of the dialogue box. You will be prompted to select a coordinate reference system to use from a list which can be filtered by SRID.
Once your coordinate system has been selected the two tables should be displayed spatially in QGIS. If you have chosen to add the extra Boolean column to the postcode area polygons table this flag will alert you to when a postcode is part of a vertical street. The vertical street lookup table can then be used to display all the postcodes contained within the vertical street.

Creating single-space postcodes

Centroids and polygons

Outward and inward bound representation

The current specification represents the postcodes in a set format that defines the postcodes as having an inward and outward postcode ‘code’. Code-Point and Code-Point with polygon postcodes have 0, 1 or 2 spaces between the in and out code.

The table below identifies how postcodes are currently shown in the data.

Postcode structure

Number of spaces

Single-space postcodes

The Code-Point and Code-Point with polygons postcodes are currently represented as above; however, there may be a user requirement to represent each postcode in a uniformed single-space format.

The aim of this section is to offer some guidance on how to process the Code-Point and the related Code-Point with polygons data to generate postcodes with a single space.

The single-space instructions are applicable to both the postcode point and unit polygon products. Microsoft Excel, Microsoft Access, MapInfo, ESRI and QGIS GIS formats have been included to provide guidance when using comma-separated values (CSV) and other formats.

The underlying theory for all of the methods is principally the same, in that all current spaces are removed and then a single space added before the third character from the right.

The NTF format is not included in this chapter as it is not compatible to a single-space format.

These instructions apply to postcode units only, and not to vertical streets (which are only found in the Code-Point with polygons dataset). To ensure that the vertical street references are not corrupted, remove them from your data before applying these instructions.

CSV single-space postcodes using Microsoft Excel and Access

Open the CSV file with Excel so that the data is displayed in columns.
In a new blank column, click in the first cell of the new column (excluding the row column names).
In the function line, enter in the following function command where A1 is the column containing the postcode: =TRIM(LEFT(A1,LEN(A1)-3))&" "&RIGHT(A1,3)

This should now produce a column containing postcodes with a single space. For polygon data, extend this formula downwards, stopping when you reach any vertical street references; for example, those beginning with ‘V’.

The same method can be employed in Microsoft Access, using an update query rather than the function line. The functions listed above are the same for Access and Excel.

MID/MIF and TAB single-space postcodes using MapInfo

The process within MapInfo is the same regardless of whether the original supply is in TAB or MID/MIF, as both get imported to MapInfo and opened as a .TAB file.

Create a new column, of Character (8) type, in the Code-Point Polygons table (CP_Polys.TAB) as column 3. Give it a meaningful name like ‘SS_Postcode’ (go to Table > Maintenance > Table Structure). Save the table.
Click on Query, Select – this brings up the Select Query dialogue box. Ensure that the Code-Point Polygons table, CP_Polys, is being selected from and enter the following expression in the that Satisfy field:

POSTCODE not like “V%”

Change the Store Results in Table field to read ‘UpdateThese1’. Click the OK button to apply the query.
The next step is to update the SS_Postcode attribute. Click Table and then the Update column tab. This opens the following dialogue box:
Ensure that the Table to Update field has ‘UpdateThese1’ as its value. From the Column to Update drop-down menu, select the previously-added column; for example, ‘SS_Postcode’, making sure the Get Value from Table is the same table as in the Table to Update field.
Click the Assist button. This opens the following Expression dialog box:

In the Type an expression box, key in the following function command:

RTrim$(Left$(<insert column name of original postcodes>,(Len<insert column name of original postcodes> (<insert column name of original postcodes>e)-3)))+" "+Right$(<insert column name of original postcodes>,3)

Click the OK button to apply the update.

This process must then be re-run for the postcodes that were originally vertical streets also:

Change the Store Results in Table field to read ‘UpdateThese2’. Click the OK button to apply the query.

POSTCODE like “V%”

Click on Query > Select – this brings up the Select Query dialogue box. Ensure that the Code-Point Polygons table, CP_Polys, is being selected from and enter the following expression in the that Satisfy field:
The next step is to update the SS_Postcode attribute. Click Table and then the Update column tab. This opens the following dialogue box:
1. Ensure that the Table to Update field has ‘UpdateThese2’ as its value. From the Column to Update drop-down menu, select the previously-added column; for example, ‘SS_Postcode’, making sure the Get Value from Table is the same table as in the Table to Update field.
2. Click the Assist button and in the Type an expression box, key in the following function command:
3. RTrim$(Left$(<insert column name of original postcodes>,(Len(<insert column name of original postcodes>)-3)))+" "+Right$(<insert column name of original postcodes>,3)
4. Click the OK button to apply the update.

If you now browse the Code-Point Polygons table you should see that the SS_Postcode column is fully populated with single-space postcodes for both ‘standard’ postcodes and vertical street postcodes. You can choose to delete the VS_Postcode column at this point, as the new SS_Postcode contains all the single- spaced postcodes for all features.

Shapefile single-space postcodes using ESRI ArcGIS

These steps assume that the data has already been imported into ArcGIS and that the user has the correct permissions to edit the Shapefile. It is advised to try this method on a copy of the original data, and not the only copy of the data, in case of error.

Once the Shapefile is open, the required new fields can be added.

Right-click on the layer in the Table of Contents (down the left-hand side of the map window) and open the Open Attribute Table.

The first step is to add a new column to hold the newly formatted postcode.

Click on the Options button then click on Add Field.

This opens the following dialogue box:
1. Key in an appropriate name, for example, ‘NewPC’, in the Name box and change the Type box on the drop-down menu to ‘text’; also change the Field Properties Precision/Length to ‘8’.
2. Click OK and the field is added.
The next stage is to ensure that only postcode units are updated and not any vertical street references that might also be in the table.
1. Click on Selection, Selection By Attributes.
This brings up the Select By Attributes dialogue box:

Ensure that the correct Layer is being selected from, in this example, ‘L’.

Ensure that the Method field you have chosen is ‘Create a new selection’.

Then, enter the following expression in the query field at the bottom of the dialogue box:

“POSTCODE” NOT LIKE ‘V%’

Click the OK button to apply the query. This selects all the postcodes that are not vertical streets from the attribute table.

The final stage is to update the new column:

To populate the fields, the table must be made editable.
Return to the map window. Do not close the attribute table as it will be required later.
Click on the Editor drop-down selection =▼.

If this toolbar is not already loaded, then right-click on an empty part of the grey area on the map window and all the available toolbars will be listed. Simply click on the Editor toolbar and it will be loaded to the toolbar.

Ensure that the correct Layer is being selected from, in this example, ‘L’.

Ensure that the Method field you have chosen is ‘Create a new selection’.

Then, enter the following expression in the query field at the bottom of the dialogue box:

In the bottom dialog box, enter the following function command:

RTrim(Left([<insert column name of original postcodes>],(Len([<insert column name of original postcodes>])-3)))+" "+Right([<insert column name of original postcodes>],3)

Ensure that the lower-left tick box Calculate selected records only is checked.

Click OK to update the column. This will update your new column with a single-space postcode.

Finally, go back to the map window, click on the Editor toolbar and select Stop editing. It will prompt to save the edits. Click Yes.

Shapefile single-space postcodes using QGIS

These steps assume that the data has already been imported into QGIS and that the user has the correct permissions to edit the Shapefile. It is advised to try this method on a copy of the original data, and not the only copy of the data, in case of error.

Once the Shapefile has been opened in QGIS it can be edited and a new field with the reformatted postcodes added.

Right-click on the layer you wish to edit in the Layers window and select Open Attribute Table.

A new column must be created to hold the newly formatted postcodes.

Select the Toggle Editing Mode button in the top left-hand corner of the attribute table. This will activate a range of other buttons in the top bar. Select the New Column button in the top right-hand corner of the attribute table.
The following dialogue box will open, prompting you to set the name and parameters of the field. Ensure you set the field type as Text (String) and set the width to 8 characters long as shown below.

When the parameters have been set click OK. The extra field will be created and will contain null values. To populate this field, select the Open Field Calculator button in the top right-hand corner of the attribute table. The following dialogue box will be opened.

Click the checkbox Update existing field and then choose the field you have created from the drop-down underneath. In the Expression box copy and paste the following code: trim(concat( left( "<insert column name of original postcodes>" , length( "<insert column name of original postcodes>" )-3) ,' ', right( "<insert column name of original postcodes>" , 3) ) )
See image below for example.
After selecting OK, the dialogue box will close, and the new column will be updated with single-spaced postcodes.

Data measures

Ordnance Survey measures the data in its products in one or more of the ways set out in the definitions of data measures table below.

Data measure

Definition

Sub-measure

Definition

* When testing the data according to the dataset specification against the ‘real world’ or reference dataset.

Code-Point with Polygons Technical Specification

This technical specification provides detailed technical information about Code-Point with Polygons. It is targeted at technical users and software developers.

This technical specification provides detailed technical information that is designed to help you fully understand the data structure of Code-Point with Polygons.

Code-Point with Polygons is a dataset that contains the notional area of postcode units, allowing customers to display and analyse any data collected at the postcode level. The polygons within the product are derived from georeferenced Royal Mail Postal Address File (PAF) delivery addresses.

For full details on the Code-Point product data structure, see the Code-Point Technical Specification.

What you need to use Code-Point with Polygons

Hardware

Code-Point with Polygons is a data product and does not include software for analysis but can be used with a variety of programs. Code-Point with Polygons can be loaded into a GIS (geographical information system) for display and analysis of the data. Consult your GIS documentation to establish actual system requirements.

Software

Most proprietary GIS packages will suffice, for example, MapInfo, ESRI or QGIS products.

Data supply

The polygon data coverage is Great Britain, the associated Code-Point coverage is for United Kingdom, as it includes Northern Ireland postcodes.

Update currency

Updates will normally be quarterly in January, April, July, and October and are a complete resupply of the national dataset.

Supply formats

Code-Point with Polygons is available in the following formats, the preferred choice of which will be influenced by the software used:

ESRI Interchange format Shapefile

ESRI Shapefile is a simple, non-topological format for storing the geometric location and attribute information of geographic features. A Shapefile is one of the spatial data formats that can be utilised in ArcGIS.

The Shapefile format defines the geometry and attributes of geographically referenced features in as many as six files with specific file extensions that should be stored in the same project workspace.

They are:

.shp – the file that stores the feature geometry.
.shx – the file that stores the index of the feature geometry.
.dbf – the dBASE file that stores the attribute information of features.
.prj – the projection file that provides the information on the coordinate reference system.
When a Shapefile is added as a theme to a view, this file is displayed as a feature table.
.sbn and .sbx – the files that store the spatial index of the features.

The last two files will only exist if you perform theme on theme selection, spatial joins, or create an index on a theme's SHAPE field.

The shapefile has two attributes (FID and SHAPE) that are virtual columns created by ArcGIS when accessing the table contents but are not visible in the attribute table. The FID column uniquely identifies each object stored in the table. The SHAPE column provides information about the feature geometry.

MapInfo Interchange format (MID / MIF)

The transfer format is as defined by the MapInfo Professional User's Guide: MIF Export. MapInfo Interchange Format (MIF) is an ASCII file format that can fully describe a MapInfo database. Both graphic and tabular data are exported into MIF files. The graphic data is in a file with a .mif extension, and the tabular data is in a file with a .mid extension.

MapInfo Table file format (TAB)

TAB files (MapInfo tables) are the native format of MapInfo. They consist of a number of files with extensions such as .DAT, .ID, .MAP and .TAB; all of these files need to be present and kept together for the table to work.

Vector tiles format (MBTiles)

Code-Point with Polygons is supplied as a national vector tiles set in a single MBTiles file (combined from individual PBF tiles). This is a lightweight set of tiles that are efficient to render in supported software, provide high-resolution data and give a seamless experience when zooming in and out. The data is supplied in Web Mercator projection (ESPG: 3857).

GeoPackage

Code-Point with Polygons is also supplied as GeoPackage. This is an open, standard, platform-independent, portable, self-describing, compact format for the transfer of geospatial data. GeoPackage is an SQLite container, the contents of which are governed by GeoPackage Encoding Standards.

Since a GeoPackage is a database container it supports direct use. This means that the data in the GeoPackage can be accessed and updated in a 'native' storage format without the need for intermediate format translations. It will effectively 'plug and play' in most GIS packages.

Supply options

Code-Point with Polygons is supplied via the following options:

Shapefile, MID / MIF and TAB formats are available either on DVD or downloaded via the OS Data Hub.
Vector tiles and GeoPackage are only available through download via the OS Data Hub.

File sizes

File sizes for Great Britain are approximately:

Shapefile: 610MB
TAB: 524MB
MID / MIF: 564MB
Vector tiles (MBTiles): 457MB
GeoPackage (GPKG): 708MB

Code-Point with Polygons version numbering

Each edition of Code-Point with Polygons will have a version number showing the release month for the year (for example, April) followed by the release year (for example, 2023).

The version for each quarterly release will be in this format:

April_2023
July_20223
October_2023
January_2024

The Code-Point data packaged alongside the postcode polygon data will be the data from the most recent Code-Point product release. Typically, this is the Code-Point release from two months prior. For example, the October 2023 release of Code-Point with Polygons will be supplied alongside the August 2023 release of Code-Point.

Specification

Content

Code-Point with Polygons contains:

The OS Code-Point product which contains georeferenced postcode unit data, alongside associated metadata such as address counts and quality indicators. Also provided are the health and administrative area codes related to each postcode. The coverage of the Code-Point data is the whole of the UK and it is provided in both comma-separated values (CSV) format and GeoPackage format.
Also provided, in association with the Code-Point data, is a text file that provides the full text equivalents of the administrative area codes, and another that provides the numbers of postcode units in each postcode area.
Postcode unit polygons depicting notional boundaries around each postcode unit in Great Britain. This data is supplied in either Shapefile, TAB, MID / MIF, vector tiles, or GeoPackage formats
Also provided, in association with the polygon data, are two sets of CSV text files containing Vertical Street, and Discard data.

Product structure

Shapefile, MID / MIF, TAB and vector tiles

The Code-Point with Polygons product contains two sets of data in two different folders:

Code-Point – This contains the OS Code-Point product, details of which can be found in the Code-Point Overview, Getting Started Guide, and Technical Specification documents.
Polygons – The Polygons folder contains the following text file:
- Licence.txt – Licence, copyright and specification change information And two sub-folders: Docs and Data.
The Docs folder contains the following file:
- Order Details.txt – Notes about the data
The Data folder contains the following sub-folders:
- Polygons – Contains polygon data in 120 postcode area files for Shapefile, MID / MIF and TAB formats, or one national file for vector tiles format.
- Discard_files – A lookup list of 120 text files of the postcodes that have not been included in the polygon creation process because either there are no AddressBase records of sufficient

PQ classification, or they are PO Box postcodes.

Vertical_streets – A lookup table of 120 text files of vertical street reference codes and the postcodes contained in them.

GeoPackage

The Code-Point with Polygons GeoPackage format contains the following text files:

Codepoint Licence.txt – Licence information.
Codepoint with Polygons Licence.txt – Licence information.

And three sub-folders: Codepoint_Resources, Data and Docs:

The Codepoint_Resources folder contains text files relating to the Code-Point product, details of which can be found in the Code-Point Overview, Getting Started Guide, and Technical Specification documents.
The Data folder contains the following sub-folders:
Data – Code-Point with Polygons GeoPackage (following the convention Geopackage_MMM_YYYY.gpkg, where MMM_YYYY are the month and year of release, respectively).
- DISCARD_FILES – A lookup list of 120 text files of the postcodes that have not been included in the polygon creation process because either there are no AddressBase records of sufficient

PQ classification, or they are PO Box postcodes.

VERTICAL_STREETS – A lookup table of 120 text files of vertical street reference codes and the postcodes contained in them.
The Docs folder contains the following text file:
- Order Details.TXT – Notes about the data (this file).

Data specification

Polygons

The file contains polygon data in 120 postcode area files in the chosen format.

The following table represents the structure of the data in Shapefile, TAB and MID / MIF formats:

For information, the attribute headers in GeoPackage are lowercase; the data structure is the same.

Example in TAB and MID / MIF: ”TA15 1PL”,00004000000001389232”,”TA”

Example of Shapefile “0”,”Polygon”,”TA15 1PL”,00004000000001389232”,”TA”

The vector tiles format contains a single file with a national set of postcode polygons in vector tiles format. The vector tiles schema is detailed in the table below. In the zoom levels columns within the table, the letter N indicates that the specified layer and attribute is not mapped within that zoom level, whereas the letter Y indicates that the specified layer and attribute is mapped within that zoom level.

Vertical street lookup

Vertical streets is a list of polygons, identified by a serial number that is prefixed by the letter V, which contain more than one postcode. This situation can occur in, for example, blocks of flats where there is more than one postcode within a single building.

The Vertical Street lookup contains 120 postcode area text files of vertical street reference codes and the postcodes contained in them.

* Denotes presence in Shapefile format only.

Example: "UB1 1ET","VUB00001"

Discard files

Discard files is a list of the postcodes for which polygons have not been included because there is no data of sufficient quality to use in the polygon creation, or because their constituent addresses lie outside the extent of the realm (coastline). Also in the discard file are PO Boxes – a list of the PO Box postcodes, none of which will have been used in the creation of the polygon set.

The Discard File lookup contains 120 postcode area text files of the postcodes.

Example: "CB1 0AH","POBOX"

Data coverage

The Code-Point product contains a point reference for every postcode unit in England, Scotland, Wales, and Northern Ireland that is contained in Royal Mail’s PAF product at the time of creation of the dataset. For further information about the Code-Point product, please refer to the Code-Point Overview, Getting Started Guide, and Technical Specification documents.

The polygon set contains a polygon for every postcode in England, Scotland, and Wales that is contained in Royal Mail’s PAF product, with the following exceptions:

Postcodes for which there are no delivery point addresses of sufficient quality.
Postcodes for which there are no delivery point addresses that lie within the extent of the realm coastline.
Postcodes that relate to PO Boxes.
Postcodes that are vertically stacked, i.e. two or more postcodes within a single building that are represented by a single large-scale building seed. In these situations, a single square polygon represents all the postcodes attributed to the single building seed.