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Code-Point Open Getting Started Guide

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

Code-Point Open locates over 1.7 million postcode units for Great Britain, each having a notional geographical location. Postcodes are an alphanumeric abbreviated form of an address. Postcode units are unique references and identify an average of 15 addresses. In some cases, where an address receives a substantial amount of mail, a postcode will apply to only one address and is defined as a large-user postcode. The maximum number of addresses in a postcode is 100.

This getting started guide focusses on using the product in comma-separated values (CSV) format.

Requirements for using the data

What you need to use Code-Point Open

Code-Point Open is a data product and does not include software for analysis but can be used with a variety of programs. Code-Point Open 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.

Supply mechanism

Code-Point Open is only available as national cover of Great Britain. The product is supplied in two formats (CSV and GeoPackage) as an online download from the OS Data Hub.

Product update schedule

Updates are supplied quarterly (February, May, August and November) and provided as a complete resupply. Any postcode that is deleted between supplies will not be included.

Coverage and file sizes

Code-Point Open covers postcodes for Great Britain. In CSV format, postcodes are divided into postcode areas and supplied as 120 files. GeoPackage format is a self-contained database.

The approximate file sizes of the respective data formats are as follows:

CSV: 153MB
GeoPackage: 257MB

Code-Point Open data structure

CSV

The Code-Point Open CSV format contains two folders in the root directory: Doc and Data The Doc folder contains the following files:

Codelist.xlsx – Lookup table of Government Statistical Service (GSS) codes.
Code-Point_Open_Column_Headers.csv – Description of column headers.
licence.txt – Important licence information.
metadata.txt – Number of postcode units in each postcode area.
NHS_Codelist.xls – Lookup table of health GSS codes.
readme.txt – Summary of supplied data.

The Data folder contains the following sub-folder:

CSV – 120 postcode area files in CSV format.

GeoPackage

The Code-Point Open GeoPackage format contains the following text file in the root directory:

Readme.txt – Summary of supplied data And two folders: Doc and Data.

The Doc folder contains the following files:

Codelist.xlsx – Lookup table of GSS codes.
Code-Point_Open_Column_Headers.csv – Description of column headers.
Licence.txt – Important licence information.
Metadata.txt – Number of postcode units in each postcode area.
NHS_Codelist.xls – Lookup table of health GSS codes The Data folder contains the following file:
- Codepo_gb.gpkg – One postcode area file in GeoPackage format.

Available formats

CSV

The structure of Code-Point Open supplied in CSV is described in the product's Technical Specification.

GeoPackage

The structure of Code-Point Open supplied in GeoPackage is described in the product's Technical Specification.

CSV file processing

As Code-Point Open data is supplied in separate .csv files by two-digit grid references, the files will require some processing in order to proceed.

The Great Britain .csv files should be combined with the Code-Point_Open_Column_Headers.csv. To do this:

Before processing the data, create the following folder:
- Great Britain

Then, copy all the .csv files from the CSV folder for Great Britain into this folder (120 in total).

Add the Code-Point_Open_Column_Headers.csv (located in the Doc folder) into the Great Britain folder and prefix the name with: aa_

Combining multiple CSV files

The following is an example of one way to combine all the individual .csv files into a single file by using a .bat batch file.

The .csv file that is created comes to approximately 150MB, and 1.7 million records. If this is opened in Microsoft Excel, only the first million records can be seen as the software cannot display more than this number of records.

To use the batch function:

Copy the following text and paste it into a new Notepad document: copy *.csv outputfile.csv
Save the Notepad document with the file extension .bat (for example, combine_csv.bat) in the Great Britain folder containing the 120 Great Britain .csv files.
Close the .bat file and navigate to the Great Britain folder, where it was saved. Double-click on the .bat file and an MS-DOS window will appear. Once the process is complete, the MS-DOS screen will close automatically.
A new CSV file with the name outputfile.csv has now been created within the Great Britain folder. All the .csv files apart from outputfile.csv can now be deleted as they have all been copied into the one ouputfile.csv.

The outputfile.csv will have two column headers at rows 1 and 2 – an abbreviated version and a full version.

Open the .csv file in a text editor (not Excel) and delete the column header that you don’t want to use, ensuring that any resulting empty row is closed.

You will now have an output file ready for uploading into geospatial software (such as QGIS).

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.

Metadata

Metadata, which is ISO 19115 UK GEMINI 2 compliant, can be found at https://www.data.gov.uk/dataset/e3d9cd8e-e702-4fc6-a674-c1f25eb5efab/ordnance-survey-code-point-open. Metadata .xml files can be found at http://www.ordnancesurvey.co.uk/oswebsite/xml/products/.

Loading the data into a GIS

The data can be loaded into several geographic information systems (GIS). This section describes how to load the combined CSV output file (for more information on how to combine multiple CSV files, see Section 3.1) into four commonly used GIS, including:

QGIS
ArcGIS Pro
ArcMap
MapInfo Pro 2019

QGIS

The following step-by-step instructions outline how to load Code-Point Open CSV files into QGIS. They have been prepared using version 3.8.1-Zanzibar of QGIS Desktop – an open-source GIS in which you can create, edit and visualise and publish geographic information. You can download QGIS for free from the Download QGIS for your platform page of the QGIS website.

Loading and displaying the CSV supply

To load and display CSV data in QGIS:

Open an existing project in QGIS or create a new one.
In Layer, click Add Layer > Add Delimited Text Layer… or click on the Add Delimited Text Layer symbol in the Manage Layers Toolbar.
This will open the Data Source Manager Delimited Text dialog.
In the Data Source Manager Delimited Text dialog:
- File name: Use the ellipsis button (…) to the right of the File name pane to navigate to the saved outputfile.csv.
- File Format: Select CSV (comma separated values).
- Record and Fields Options: Select First Record has field names.
- Geometry Definition:
  - Select Point coordinates.
  - X field: Choose Eastings (or EA if the abbreviated column header was selected).
  - Y field: Choose Northings (or NO if the abbreviated column header was selected).
  - Geometry CRS: Select EPSG:27700 – OSGB 1936 / British National Grid.
- Click Add.
  It will take a minute or so to load the data into the map pane, but when it has finished, the map pane will look like the example below:
  OS Maps API Light 27700 is being used as the background map for geographic context
The outputfile can now be saved out into any format of your choosing. It is best to do this, otherwise you will have to repeat the process of geoprocessing the outputfile.csv every time you need to use it.

ArcGIS Pro

The following step-by-step instructions outline how to load Code-Point Open CSV files into ArcGIS Pro. They have been prepared using version 3.0.

Loading and displaying the CSV supply

To load and display CSV data in ArcGIS Pro:

Open ArcGIS Pro.
Open a project and name it (in this example, the project will be called cpOpen).
1. Browse to a memorable location in which to save the project and keep the ‘Create a new folder for this project’ option checked.
2. Click OK.
3. Once the project opens, add a background map for geographic context (in this example, OS Maps API Light 27700 has been added as the background map).
4. From the Map tab, click Add Data > XY Point Data.
  A Geoprocessing pane will open on the right-hand side of the map pane.
5. Input Table: Use the folder symbol to the right of the field to navigate to the outputfile.csv.
  - Output Feature Class: This will auto-populate.
  - X Field: Select Easting (or EA if the abbreviated column headers were chosen).
  - Y Field: Select Northing (or NO if the abbreviated column headers were chosen).
  - Coordinate System: Select Current Map [Map]. This will then populate with British National Grid (the OS Maps API Light 27700 map has already been chosen for the background context mapping in this example).
  - Click Run at the bottom right of the Geoprocessing pane.
  In the Geoprocessing pane:
  - Input Table: Use the folder symbol to the right of the field to navigate to the outputfile.csv.
  - Output Feature Class: This will auto-populate.
  - X Field: Select Easting (or EA if the abbreviated column headers were chosen).
  - Y Field: Select Northing (or NO if the abbreviated column headers were chosen).
  - Coordinate System: Select Current Map [Map]. This will then populate with British National Grid (the OS Maps API Light 27700 map has already been chosen for the background context mapping in this example).
  - Click Run at the bottom right of the Geoprocessing pane.
    It will take a minute or so to load the data into the map pane, but when the data has finished loading, the map pane will look like the example below:
    OS Maps API Light 27700 has been used as the background map for geographic context.
    As a result of this process, a new file geodatabase will have been created in the new folder that was created when the project was opened.

ArcMap

The following step-by-step instructions outline how to load Code-Point Open CSV files into ArcMap. They have been prepared using version 10.7.1.

Loading and displaying the CSV supply

To load and display CSV data in ArcMap:

Open ArcMap.
Click on the Add Data button from the top ribbon.
In the Add Data dialog, browse to where you have saved your outputfile.csv, select the file and click Add.
The file will now appear in the Table Of Contents.
Right-click on the outputfile.csv in the Table of Contents and select Display XY data…
In the Display XY Data dialog:
1. X Field: Select Eastings (or EA if the abbreviated column headers have been chosen).
2. Y Field: Select Northings (or NO if the abbreviated column headers have been chosen).
3. Coordinate System of the Input Coordinates: Select British National Grid.
4. Click OK.
Click OK in the following window which will automatically pop up:
The message warns you that the file resulting layer is only a temporary table and will need to be saved out.
After a minute or so, the points will appear in the map pane; the map pane should look similar to the following example:
Before the points can be used meaningfully, you'll need to save the layer out as a shapefile:
- Right-click on the outputfile.csv Events layer in the Layers panel.
- Click Export from the drop-down menu.
- In the Export Data dialog, browse to and select a file name for the data.
- Click OK.
  The shapefile will take several minutes to create, but progress can be monitored in the Export Progress window that will automatically pop up. This window will close when the export is complete.
The following window will also pop up, giving you the option to add the newly created data to the workspace. If you click Yes, then a shapefile and associated files will be created at the chosen location.

MapInfo Pro

The following step-by-step instructions outline how to load Code-Point Open CSV files into MapInfo Pro. They have been prepared using version MapInfo Pro 2019, release build 58.

Loading and displaying the CSV supply

To load and display CSV data in MapInfo Pro:

Open MapInfo Pro 2019.
Select Open > Blank Workspace.

Open a mapping background for geographic context (in this example, OS Maps API Light 27700 has been added as the background map).

From the HOME tab, click Open Table.
In the Open dialog:
- Files of type: Change from MapInfo.tab to Comma delimited CSV (*.csv).
- Browse to outputfile.csv and click on it.
- Click Open.
In the Open dialog:
- Files of type: Change from MapInfo.tab to Comma delimited CSV (*.csv).
- Browse to outputfile.csv and click on it.
- Click Open.
  It will take several minutes for the table to load, but when it does, a window called outputfile Browser will open:
To create the points from the table, click on the SPATIAL tab from the top ribbon > Create > Create Points.
In the Create Points dialog:
- Projection: Change this from Longitude / Latitude (WGS 84) to British National Grid [EPSG:27700]. The easiest way to do this is to click the ellipsis button next to Projection and then tap B on the keyboard 6 times, highlight British National Grid [EPSG:27700] in the results and click OK.
- using Symbol: The default style in this dialog is a square. You can change this to something a bit more visible (for example, a red star) if you like by clicking on the ‘using Symbol’ button and following the instructions.
- Leave all the other settings.
- Click OK.
  A progress bar will appear; it will disappear when the geoprocessing has finished:
  Once the process has finished, the points will appear in the map pane with your chosen point style. The map pane should look similar to the following example:
  A .tab file (and associated .MAP and .ID files) is automatically created in the same folder as the outputfile.csv. However, these are the temporary files that are created as part of the point creation process and they will be difficult to query.

To save the output file layer as a true .tab file, click the HOME tab > Save > Save Copy As. In the Save Copy As dialog, select outputfile and click Save As…

In the Save Copy of Table As dialog, navigate to where you would like to save the .tab file, give it a memorable name and click Save:
A progress bar will once again appear and then disappear when the save has completed. A more easily queryable .tab file will now be available to use in MapInfo.

Glossary

Glossary term

Definition

Loading the data into a GIS

QGIS
ArcGIS Pro
ArcMap
MapInfo Pro 2019

QGIS

Loading and displaying the CSV supply

To load and display CSV data in QGIS:

Open an existing project in QGIS or create a new one.
In Layer, click Add Layer > Add Delimited Text Layer… or click on the Add Delimited Text Layer symbol in the Manage Layers Toolbar.
This will open the Data Source Manager Delimited Text dialog.
In the Data Source Manager Delimited Text dialog:
- File name: Use the ellipsis button (…) to the right of the File name pane to navigate to the saved outputfile.csv.
- File Format: Select CSV (comma separated values).
- Record and Fields Options: Select First Record has field names.
- Geometry Definition:
  - Select Point coordinates.
  - X field: Choose Eastings (or EA if the abbreviated column header was selected).
  - Y field: Choose Northings (or NO if the abbreviated column header was selected).
  - Geometry CRS: Select EPSG:27700 – OSGB 1936 / British National Grid.
- Click Add.
  It will take a minute or so to load the data into the map pane, but when it has finished, the map pane will look like the example below:
  OS Maps API Light 27700 is being used as the background map for geographic context
The outputfile can now be saved out into any format of your choosing. It is best to do this, otherwise you will have to repeat the process of geoprocessing the outputfile.csv every time you need to use it.

ArcGIS Pro

The following step-by-step instructions outline how to load Code-Point Open CSV files into ArcGIS Pro. They have been prepared using version 3.0.

Loading and displaying the CSV supply

To load and display CSV data in ArcGIS Pro:

Open ArcGIS Pro.
Open a project and name it (in this example, the project will be called cpOpen).
1. Browse to a memorable location in which to save the project and keep the ‘Create a new folder for this project’ option checked.
2. Click OK.
3. Once the project opens, add a background map for geographic context (in this example, OS Maps API Light 27700 has been added as the background map).
4. From the Map tab, click Add Data > XY Point Data.
  A Geoprocessing pane will open on the right-hand side of the map pane.
5. Input Table: Use the folder symbol to the right of the field to navigate to the outputfile.csv.
  - Output Feature Class: This will auto-populate.
  - X Field: Select Easting (or EA if the abbreviated column headers were chosen).
  - Y Field: Select Northing (or NO if the abbreviated column headers were chosen).
  - Coordinate System: Select Current Map [Map]. This will then populate with British National Grid (the OS Maps API Light 27700 map has already been chosen for the background context mapping in this example).
  - Click Run at the bottom right of the Geoprocessing pane.
  In the Geoprocessing pane:
  - Input Table: Use the folder symbol to the right of the field to navigate to the outputfile.csv.
  - Output Feature Class: This will auto-populate.
  - X Field: Select Easting (or EA if the abbreviated column headers were chosen).
  - Y Field: Select Northing (or NO if the abbreviated column headers were chosen).
  - Coordinate System: Select Current Map [Map]. This will then populate with British National Grid (the OS Maps API Light 27700 map has already been chosen for the background context mapping in this example).
  - Click Run at the bottom right of the Geoprocessing pane.
    It will take a minute or so to load the data into the map pane, but when the data has finished loading, the map pane will look like the example below:
    OS Maps API Light 27700 has been used as the background map for geographic context.
    As a result of this process, a new file geodatabase will have been created in the new folder that was created when the project was opened.

ArcMap

The following step-by-step instructions outline how to load Code-Point Open CSV files into ArcMap. They have been prepared using version 10.7.1.

Loading and displaying the CSV supply

To load and display CSV data in ArcMap:

Open ArcMap.
Click on the Add Data button from the top ribbon.
In the Add Data dialog, browse to where you have saved your outputfile.csv, select the file and click Add.
The file will now appear in the Table Of Contents.
Right-click on the outputfile.csv in the Table of Contents and select Display XY data…
In the Display XY Data dialog:
1. X Field: Select Eastings (or EA if the abbreviated column headers have been chosen).
2. Y Field: Select Northings (or NO if the abbreviated column headers have been chosen).
3. Coordinate System of the Input Coordinates: Select British National Grid.
4. Click OK.
Click OK in the following window which will automatically pop up:
The message warns you that the file resulting layer is only a temporary table and will need to be saved out.
After a minute or so, the points will appear in the map pane; the map pane should look similar to the following example:
Before the points can be used meaningfully, you'll need to save the layer out as a shapefile:
- Right-click on the outputfile.csv Events layer in the Layers panel.
- Click Export from the drop-down menu.
- In the Export Data dialog, browse to and select a file name for the data.
- Click OK.
  The shapefile will take several minutes to create, but progress can be monitored in the Export Progress window that will automatically pop up. This window will close when the export is complete.
The following window will also pop up, giving you the option to add the newly created data to the workspace. If you click Yes, then a shapefile and associated files will be created at the chosen location.

MapInfo Pro

The following step-by-step instructions outline how to load Code-Point Open CSV files into MapInfo Pro. They have been prepared using version MapInfo Pro 2019, release build 58.

Loading and displaying the CSV supply

To load and display CSV data in MapInfo Pro:

Open MapInfo Pro 2019.
Select Open > Blank Workspace.

Open a mapping background for geographic context (in this example, OS Maps API Light 27700 has been added as the background map).

From the HOME tab, click Open Table.
In the Open dialog:
- Files of type: Change from MapInfo.tab to Comma delimited CSV (*.csv).
- Browse to outputfile.csv and click on it.
- Click Open.
In the Open dialog:
- Files of type: Change from MapInfo.tab to Comma delimited CSV (*.csv).
- Browse to outputfile.csv and click on it.
- Click Open.
  It will take several minutes for the table to load, but when it does, a window called outputfile Browser will open:
To create the points from the table, click on the SPATIAL tab from the top ribbon > Create > Create Points.
In the Create Points dialog:
- Projection: Change this from Longitude / Latitude (WGS 84) to British National Grid [EPSG:27700]. The easiest way to do this is to click the ellipsis button next to Projection and then tap B on the keyboard 6 times, highlight British National Grid [EPSG:27700] in the results and click OK.
- using Symbol: The default style in this dialog is a square. You can change this to something a bit more visible (for example, a red star) if you like by clicking on the ‘using Symbol’ button and following the instructions.
- Leave all the other settings.
- Click OK.
  A progress bar will appear; it will disappear when the geoprocessing has finished:
  Once the process has finished, the points will appear in the map pane with your chosen point style. The map pane should look similar to the following example:
  A .tab file (and associated .MAP and .ID files) is automatically created in the same folder as the outputfile.csv. However, these are the temporary files that are created as part of the point creation process and they will be difficult to query.

To save the output file layer as a true .tab file, click the HOME tab > Save > Save Copy As. In the Save Copy As dialog, select outputfile and click Save As…

In the Save Copy of Table As dialog, navigate to where you would like to save the .tab file, give it a memorable name and click Save:
A progress bar will once again appear and then disappear when the save has completed. A more easily queryable .tab file will now be available to use in MapInfo.