W postcode district map, London
Supplier statuses last checked .
The W postcode area covers 26 districts and 18,480 live postcodes, from W2 to W1W. It is centred on London and also covers City of Westminster, Sunbury-on-Thames and City of London.
Districts here average 711 postcodes.
Where the W districts sit
12 districts are plotted without a label where labels would overlap; every one is in the table below.
Where W sits
The whole area sits inside Greater London, which is unusual at this size.
Water supply across W
All 26 W 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 W.
The shape of the W area
W3 is the largest district with 1,158 postcodes around London, and W1C the smallest with 141. The area divides into 141 postcode sectors.
No single district dominates: the largest holds only about 6 per cent of the area's postcodes.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: W2, W3, W4, W5, W8, W9, W10, W11, W12, W1B, W1C, W1D, W1F, W1G, W1H, W1J, W1K, W1S, W1T, W1U and W1W all point at London, W6 and W14 all point at City of Westminster and W7 and W13 all point at Sunbury-on-Thames.
What borders W
W sits next to SW (City of Westminster) to the south east, WC (London) to the east, NW (London) to the north, EC (City of London) to the east and N (City of London) to the north east.
Its neighbours run in 4 different directions, so W is landlocked by other postcode areas on most sides.
W districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| W2 | London | Thames Water | Ban in force |
| W3 | London | Thames Water | Ban in force |
| W4 | London | Thames Water | Ban in force |
| W5 | London | Thames Water | Ban in force |
| W6 | City of Westminster | Thames Water | Ban in force |
| W7 | Sunbury-on-Thames | Thames Water | Ban in force |
| W8 | London | Thames Water | Ban in force |
| W9 | London | Thames Water | Ban in force |
| W10 | London | Thames Water | Ban in force |
| W11 | London | Thames Water | Ban in force |
| W12 | London | Thames Water | Ban in force |
| W13 | Sunbury-on-Thames | Thames Water | Ban in force |
| W14 | City of Westminster | Thames Water | Ban in force |
| W1A | City of London | Thames Water | Ban in force |
| W1B | London | Thames Water | Ban in force |
| W1C | London | Thames Water | Ban in force |
| W1D | London | Thames Water | Ban in force |
| W1F | London | Thames Water | Ban in force |
| W1G | London | Thames Water | Ban in force |
| W1H | London | Thames Water | Ban in force |
| W1J | London | Thames Water | Ban in force |
| W1K | London | Thames Water | Ban in force |
| W1S | London | Thames Water | Ban in force |
| W1T | London | Thames Water | Ban in force |
| W1U | London | Thames Water | Ban in force |
| W1W | 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 W
No water company covering W 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 |
|---|---|---|---|---|
| W2 | Not published by Thames Water. Check with your supplier. | |||
| W3 | Not published by Thames Water. Check with your supplier. | |||
| W4 | Not published by Thames Water. Check with your supplier. | |||
| W5 | Not published by Thames Water. Check with your supplier. | |||
| W6 | Not published by Thames Water. Check with your supplier. | |||
| W7 | Not published by Thames Water. Check with your supplier. | |||
| W8 | Not published by Thames Water. Check with your supplier. | |||
| W9 | Not published by Thames Water. Check with your supplier. | |||
| W10 | Not published by Thames Water. Check with your supplier. | |||
| W11 | Not published by Thames Water. Check with your supplier. | |||
| W12 | Not published by Thames Water. Check with your supplier. | |||
| W13 | Not published by Thames Water. Check with your supplier. | |||
| W14 | Not published by Thames Water. Check with your supplier. | |||
| W1A | Not published by Thames Water. Check with your supplier. | |||
| W1B | Not published by Thames Water. Check with your supplier. | |||
| W1C | Not published by Thames Water. Check with your supplier. | |||
| W1D | Not published by Thames Water. Check with your supplier. | |||
| W1F | Not published by Thames Water. Check with your supplier. | |||
| W1G | Not published by Thames Water. Check with your supplier. | |||
| W1H | Not published by Thames Water. Check with your supplier. | |||
| W1J | Not published by Thames Water. Check with your supplier. | |||
| W1K | Not published by Thames Water. Check with your supplier. | |||
| W1S | Not published by Thames Water. Check with your supplier. | |||
| W1T | Not published by Thames Water. Check with your supplier. | |||
| W1U | Not published by Thames Water. Check with your supplier. | |||
| W1W | 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 W 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 W area?
There are 26 W postcode districts, running from W2 to W1W, and they contain 18,480 live postcodes across 141 sectors.
What towns does the W postcode area cover?
W covers London, City of Westminster, Sunbury-on-Thames and City of London. 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 W postcodes?
Thames Water supplies all 26 W 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 W2 and W3 both say London?
W2, W3, W4, W5, W8, W9, W10, W11, W12, W1B, W1C, W1D, W1F, W1G, W1H, W1J, W1K, W1S, W1T, W1U and W1W 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 W postcode map?
Yes. This page offers the W 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.
How many postcode sectors are in W?
W contains 141 postcode sectors across its 26 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.
Is there a hosepipe ban in W?
Yes, across the area: Thames Water has a restriction in force covering W. The table on this page shows the position district by district.