N postcode district map, City of London

Where the N districts sit

1 district is plotted without a label where labels would overlap; every one is in the table below.

Where N sits

The whole area sits inside Greater London, which is unusual at this size.

Water supply across N

All 25 N districts are supplied by Thames Water, which is notable at this size: an area with this many districts usually crosses at least one supply boundary, and this one does not.

Thames Water has a hosepipe ban in force from 23 July 2026, covering the whole of N.

The shape of the N area

The districts are wildly uneven: N1 holds 2,289 postcodes around City of London and N81 holds 3, a ratio of about 763 to one. They divide into 112 sectors.

The numbering is not continuous. N runs up to 81 but has only 25 districts, so 58 numbers are unused:.

Several districts share a settlement, which is a common source of confusion when a form rejects an address: N1, N4, N5, N7, N8, N10, N15, N16, N17, N19, N22, N81 and N1P all point at City of London, N9, N13, N18 and N21 all point at Waltham Cross and N2, N6 and N1C all point at London.

What borders N

N sits next to NW (London) to the west, WC (London) to the south, EC (City of London) to the south, E (City of London) to the east and W (London) to the south west.

Its neighbours run in 4 different directions, so N is landlocked by other postcode areas on most sides.

N districts, settlements and water supply

Principal settlement is the town or city each district sits in or nearest to, derived from OS Open Names. It is not the Royal Mail post town, which is licensed data and not published openly. Status is resolved live from each company’s own notice.

Water hardness in N

No water company covering N publishes hardness figures as open data. The gap is named per district below so you know who to ask.

Hardness is published per census area, not per postcode, so these figures characterise a district rather than measuring one address. They are a scale and taste matter, not a safety one. Hardness data version wessex-water@2022-2025+yorkshire-water@2026.

Download the N data

No signup, no email wall. GeoJSON carries the district points, the supplier and the live status, so it can be dropped straight into a map.

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District positions are averaged postcode centroids from OS Code-Point Open. They show roughly where a district sits, not where its boundary runs, and are not legal boundaries.

Frequently asked questions