Code-Point support

It can take some time for a new postcode to work its way through the system into Code-Point®. Until our surveyors have visited the area to complete the very precise large-scale mapping, we allocate a calculated map reference to the postcode that, depending on the level of development in the area, can be somewhat inaccurate. When this has been done, a positional quality indicator in the Code-Point record makes it clear that the coordinates provided are temporary, and will be improved to a full quality match as soon as possible.

Code-Point includes 121 postcode areas in England, Scotland, Wales and Northern Ireland, but does not include the postcode areas for the Isle of Man or the Channel Islands.

The product is updated every three months (February, May, August and November).

GridLink® is a joint consortium dataset that provides geospatially referenced postcode data, consisting of UK postcodes, administration areas and health authority codes.

The GridLink® Consortium comprises Royal Mail®, Ordnance Survey®, the Office for National Statistics (ONS), Land & Property Services (LPS) and National Records of Scotland (NRS). Each consortium member supplies component data to create the GridLink® dataset.

More often than not, this is the result of the recoding of an area by Royal Mail. This can happen for various reasons, usually because there are more postcodes required than there is capacity within the higher-level aggregations of postcodes, known as postcode sectors, districts and areas. The postcodes will therefore change, for example, from RG1 1AA to RG10 1AA.

Changes to Royal Mail postcodes may result in some postcodes being deleted and therefore no longer represented in the product.

The postcodes in Code-Point Open and Code-Point are for ‘live’ postcodes only that Royal Mail are currently delivering too. If Royal Mail aren’t delivering to these addresses then the postcodes won’t be in any of the Ordnance Survey postcode products. They will be reinstated if, and when, Royal Mail deliver post to those addresses again.

To answer this question, it is important to understand the difference between 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.

When used in an address the inward code (incode) should be separated from the outward code (outcode) by a single space, however, within the supplied Code-Point products there may be 0, 1 or 2 spaces between these two elements.

The postcode field is set at seven characters. The varying number of spaces in this field is determined by the number of characters in the postcode and parameters within the production system that stipulate the use of seven characters. Instructions are provided within the User Guide (link) for how to create single space postcodes.

Northern Ireland postcode information within Code-Point includes Irish Grid co-ordinates, as used by Ordnance Survey Ireland and Ordnance Survey Northern Ireland, rather than British Grid co-ordinates. Therefore the BT postcode area will need to be geo-referenced to the Irish Grid (PDF) within a GIS.

These are either PO Boxes or Council Area postcodes, neither of which are assigned co-ordinates by Land & Property Services. They will have a positional quality indicator (PQI) of 90 in the data.

Code-Point contains five admin ward codes for postcodes on the Isles of Scilly. These have been issued by ONS for statistical purposes only, because there are no wards on the Isles of Scilly. The Codelist.xls file supplied with Code-Point is generated from Boundary-Line. Boundary-Line does not contain these ward codes as they do not exist for political purposes. Therefore, these codes are not available in the Codelist.xls file supplied in the Doc folder with Code-Point. All other ward codes should exist in both Code-Point and the Codelist.xls file.

Combining (concatenating) multiple CSV files
It may be beneficial to combine all CSV files to ensure that the user does not have to follow the import procedure for each of the individual files, which can be time consuming and repetitive. Here is an explanation of one way to combine all the individual CSV files in to a single file by using a .bat batch file.

To use the batch function:

• Copy the following text and paste it into a new Notepad document: copy *.csv outputfile.csv
  N.B., outputfile.csv can be any user defined file name with the extension .csv, e.g. CPO_National.csv
• Save the Notepad document with the file extension .bat (e.g. combine.bat) in the same directory as the CSV files.
• Close the .bat file, and navigate to the directory where it was saved. Double click on the .bat file (i.e. merge.bat) and an MS-DOS window will appear, once the process is complete the MS-DOS screen will close automatically.
• If you navigate to the location where all of the CSV files were originally downloaded and where the .bat file was created, you will notice that there is a new CSV file with the user defined name inserted in the .bat file.

Note: 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 65,536 records can be seen as the software cannot display more than this number of records.