Code-Point Technical Specification

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

Code-Point is a dataset that contains postcode units for Great Britain and Northern Ireland, 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.

Product structure

Attributes

Attribute	Description
Postcode	Contains elements for postal area, district, sector, and unit.
Positional quality indicator (PQI)	A flag used to indicate the positional accuracy of the coordinates allocated to each postcode record.
PO Box indicator	Denotes if the postcode is a PO Box.
Total delivery points	The total number of both matched and unmatched delivery points in the postcode. Not in BT data for Northern Ireland.
Delivery points	Number of matched addresses in the postcode unit that have a PQI of 10 or 20. Not in BT data for Northern Ireland.
Domestic delivery points	Number of non PO box delivery points that have no PAF organisation name. Not in BT data for Northern Ireland.
Non domestic delivery	Number of non PO box delivery points that have a PAF organisation name. Not in BT data for Northern Ireland.
PO Box domestic delivery points	Number of PO Box delivery points. Not in BT data for Northern Ireland or where PQI is 20 in Scotland.
Matched addressed premises	Number of delivery points in buildings or building subdivisions, after exclusion of duplicated coordinate pairs. Not in BT data for Northern Ireland or where PQI is 20 in Scotland.
Unmatched delivery points	Number of delivery points awaiting improvement on location. Not in BT data for Northern Ireland or where PQI is 20 in Scotland.
Easting	Distance in metres east of National Grid origin.
Northing	Distance in metres north of National Grid origin.
Country code	Code used by ONS to identify the country in which the Code Point georeferenced coordinates lies.
NHS regional health authority code	English Pan Strategic Health Authority in which CPLC falls.
NHS health authority code	English Strategic Health Authority or Scottish Health Board in which CPLC falls.
Administrative county code	County in which CPLC falls.
Administrative district code	Unitary Authority, Metropolitan and Non- Metropolitan District, London Borough or Scottish Council Area in which CPLC falls.
Administrative ward code	Electoral Ward or Division in which CPLC falls.
Postcode type	Indicates whether the user is large, L, or small, S. Large postcode type users receive more than 500 pieces of mail. Small users receive 70 pieces per day.

Each postcode unit location – also known as CPLC (Code-Point Location Co-ordinate) – is coordinated on the respective National Grid, with eastings and northings quoted to a resolution of 1m. The accuracy of each postcode unit coordinate pair is defined by the positional quality indicator (PQI), which provides a quality statement of that Code-Point record. There are seven PQI values for the positional quality:

PQI	Description
10	Within the building of the matched address closest to the postcode mean determined automatically by Ordnance Survey (or Land & Property Services for the BT postcode area only).
20	As above but determined by visual inspection by National Records of Scotland (NRS).
30	Approximate to within 50m of the true position (postcodes relating to developing sites may be within 100m of true position).
40	The mean of the positions of addresses previously matched in PALF but which have subsequently been deleted or recoded (very rarely used).
50	Estimated position based on surrounding postcode coordinates, usually to 100m resolution, but 10m in Scotland.
60	Postcode sector mean.
90	No coordinates available.