NW postcode district map, London
Supplier statuses last checked .
The NW postcode area covers 13 districts and 14,255 live postcodes, from NW1 to NW1W. It is centred on London and also covers Borehamwood.
It is a dense area by postcode standards: an average of 1,097 postcodes per district,.
Where the NW districts sit
1 district is plotted without a label where labels would overlap; every one is in the table below.
Where NW sits
The whole area sits inside Greater London, which is unusual at this size.
Water supply across NW
All 13 NW districts are supplied by Thames Water. That makes NW simple in a way many areas are not: one company, one set of rules, one status to check.
Thames Water has a hosepipe ban in force from 23 July 2026, covering the whole of NW.
The shape of the NW area
NW10 is the largest district with 1,849 postcodes around London, and NW26 the smallest with 39. The area divides into 85 postcode sectors.
The numbering is not continuous. NW runs up to 26 but has only 13 districts, so 14 numbers are unused:.
District by district: NW1 serves London, NW2 serves London, NW3 serves London, NW4 serves Borehamwood, NW5 serves London, NW6 serves London, NW7 serves Borehamwood, NW8 serves London, NW9 serves Borehamwood, NW10 serves London, NW11 serves London, NW26 serves London and NW1W serves London.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: NW1, NW2, NW3, NW5, NW6, NW8, NW10, NW11, NW26 and NW1W all point at London and NW4, NW7 and NW9 all point at Borehamwood.
What borders NW
NW sits next to N (City of London) to the east, W (London) to the south, WC (London) to the south east, EC (City of London) to the south east and HA (Bushey) to the west.
Its neighbours run in 4 different directions, so NW is landlocked by other postcode areas on most sides.
NW districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| NW1 | London | Thames Water | Ban in force |
| NW2 | London | Thames Water | Ban in force |
| NW3 | London | Thames Water | Ban in force |
| NW4 | Borehamwood | Thames Water | Ban in force |
| NW5 | London | Thames Water | Ban in force |
| NW6 | London | Thames Water | Ban in force |
| NW7 | Borehamwood | Thames Water | Ban in force |
| NW8 | London | Thames Water | Ban in force |
| NW9 | Borehamwood | Thames Water | Ban in force |
| NW10 | London | Thames Water | Ban in force |
| NW11 | London | Thames Water | Ban in force |
| NW26 | London | Thames Water | Ban in force |
| NW1W | London | Thames Water | Ban in force |
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 NW
No water company covering NW publishes hardness figures as open data. The gap is named per district below so you know who to ask.
| District | Hardness | As published | Supply zone | Published by |
|---|---|---|---|---|
| NW1 | Not published by Thames Water. Check with your supplier. | |||
| NW2 | Not published by Thames Water. Check with your supplier. | |||
| NW3 | Not published by Thames Water. Check with your supplier. | |||
| NW4 | Not published by Thames Water. Check with your supplier. | |||
| NW5 | Not published by Thames Water. Check with your supplier. | |||
| NW6 | Not published by Thames Water. Check with your supplier. | |||
| NW7 | Not published by Thames Water. Check with your supplier. | |||
| NW8 | Not published by Thames Water. Check with your supplier. | |||
| NW9 | Not published by Thames Water. Check with your supplier. | |||
| NW10 | Not published by Thames Water. Check with your supplier. | |||
| NW11 | Not published by Thames Water. Check with your supplier. | |||
| NW26 | Not published by Thames Water. Check with your supplier. | |||
| NW1W | Not published by Thames Water. Check with your supplier. | |||
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 NW 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.
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
How many postcode districts are in the NW area?
There are 13 NW postcode districts, running from NW1 to NW1W, and they contain 14,255 live postcodes across 85 sectors.
What towns does the NW postcode area cover?
NW covers London and Borehamwood. The area takes its name from London, and each district is listed with its settlement in the table on this page.
Which water company supplies NW postcodes?
Thames Water supplies all 13 NW districts. Supply boundaries follow the pipe network rather than postcode geography, so confirm against your water bill if you are near the edge of the area.
Why do NW1 and NW2 both say London?
NW1, NW2, NW3, NW5, NW6, NW8, NW10, NW11, NW26 and NW1W all serve London, covering different parts of it. A single town routinely needs more than one postcode district once it passes a few thousand delivery points, so this is normal rather than an error in an address.
Can I download a free NW postcode map?
Yes. This page offers the NW districts as GeoJSON, CSV and SVG, free and with no signup or email address required. The GeoJSON carries each district's position, its water company and its current restriction status, so it can be dropped straight into a mapping tool.
Why is there no NW25 postcode district?
NW25 is not in use. Postcode districts are allocated as sorting requirements change rather than numbered straight through, and a code that is retired or never brought into service is not reissued, so gaps in the sequence are normal.
How many postcode sectors are in NW?
NW contains 85 postcode sectors across its 13 districts. A sector is the district plus the first digit of the second half of the postcode, and it is the level a delivery round is actually planned around.