Full postcode gives an exact match · just a district (e.g. CF10) or sector (e.g. CF10 1) shows the breakdown if it's split across zones — click a zone in that breakdown to see which postcodes it covers.
Uploaded tables keep all their original columns, with the results added on the end — the postcode column is found by its header (e.g. Postcode), or by its contents if there's no header. Everything runs in your browser; nothing is uploaded anywhere.
Shown at simplified resolution for a fast-loading overview — the postcode search above uses the full-precision boundaries. Zones are coloured by company only here (hover for the zone name); tiny (<1km²) gaps between neighbouring zones of the same company — digitisation noise in the source data — are visually closed, while genuine larger gaps, like the ~103km² hole near the Wye Valley, are left visible. Basemap: Esri World Street Map.
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The same data this tool searches, as files — for spreadsheets, GIS software, or your own analysis.