Address Point is a mapping/GIS data product supplied by Great Britain's national mapping agency, Ordnance Survey.
The history of Ordnance Survey's spatial address information goes back to the 1840s when the first large-scale maps were published with names identifying prominent properties such as large landmark houses in a locality.
In 1945, when Ordnance Survey had moved to the National Grid system, maps at 1:1250 and 1:2500 scales showed sufficient information to infer other individual addresses.
Each address is coordinated on the National Grid, with eastings and northings normally quoted to a resolution of 0.1 metres.
The accuracy of each georeference is classified within the status flag, in which is indicated whether the coordinates are due to be improved (PQ1) or as good as they can be (PQ3).