BB postcode district map, Blackburn
Supplier statuses last checked .
The BB postcode area covers 13 districts and 13,608 live postcodes, from BB1 to BB18. It is centred on Blackburn and also covers Burnley, Church, Nelson, Rawtenstall and Clitheroe.
It is a dense area by postcode standards: an average of 1,047 postcodes per district,.
Where the BB districts sit
Where BB sits
It falls across Lancashire and Blackburn with Darwen.
Water supply across BB
All 13 BB districts are supplied by United Utilities. That makes BB simple in a way many areas are not: one company, one set of rules, one status to check.
No hosepipe ban currently applies anywhere in BB.
The shape of the BB area
BB5 is the largest district with 1,552 postcodes around Church, and BB6 the smallest with 373. The area divides into 74 postcode sectors.
The numbering is not continuous. BB runs up to 18 but has only 13 districts, so 5 numbers are unused:.
District by district: BB1 serves Blackburn, BB2 serves Blackburn, BB3 serves Darwen, BB4 serves Rawtenstall, BB5 serves Church, BB6 serves Great Harwood, BB7 serves Clitheroe, BB8 serves Colne, BB9 serves Nelson, BB10 serves Burnley, BB11 serves Burnley, BB12 serves Padiham and BB18 serves Barnoldswick.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: BB1 and BB2 all point at Blackburn and BB10 and BB11 all point at Burnley.
What borders BB
BB sits next to BL (Bolton) to the south, BD (Bradford) to the north east, OL (Oldham) to the south east, HX (Halifax) to the east and PR (Preston) to the west.
Its neighbours run in 5 different directions, so BB is landlocked by other postcode areas on most sides.
BB districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| BB1 | Blackburn | United Utilities | No restrictions |
| BB2 | Blackburn | United Utilities | No restrictions |
| BB3 | Darwen | United Utilities | No restrictions |
| BB4 | Rawtenstall | United Utilities | No restrictions |
| BB5 | Church | United Utilities | No restrictions |
| BB6 | Great Harwood | United Utilities | No restrictions |
| BB7 | Clitheroe | United Utilities | No restrictions |
| BB8 | Colne | United Utilities | No restrictions |
| BB9 | Nelson | United Utilities | No restrictions |
| BB10 | Burnley | United Utilities | No restrictions |
| BB11 | Burnley | United Utilities | No restrictions |
| BB12 | Padiham | United Utilities | No restrictions |
| BB18 | Barnoldswick | United Utilities | No restrictions |
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 BB
Figures are in milligrams per litre as calcium carbonate, the unit UK water companies report in. 1 of 13 districts has a published figure.
United Utilities does not publish hardness as open data, but does publish a water hardness factsheet with a full band table and a postcode water quality checker.
| District | Hardness | As published | Supply zone | Published by |
|---|---|---|---|---|
| BB1 | Not published by United Utilities. Check with your supplier. | |||
| BB2 | Not published by United Utilities. Check with your supplier. | |||
| BB3 | Not published by United Utilities. Check with your supplier. | |||
| BB4 | Not published by United Utilities. Check with your supplier. | |||
| BB5 | Not published by United Utilities. Check with your supplier. | |||
| BB6 | Not published by United Utilities. Check with your supplier. | |||
| BB7 | Not published by United Utilities. Check with your supplier. | |||
| BB8 | Not published by United Utilities. Check with your supplier. | |||
| BB9 | Not published by United Utilities. Check with your supplier. | |||
| BB10 | Not published by United Utilities. Check with your supplier. | |||
| BB11 | Not published by United Utilities. Check with your supplier. | |||
| BB12 | Not published by United Utilities. Check with your supplier. | |||
| BB18 | 16.9 mg/l That is very soft on the water industry scale. | 16.9 mg/l as CaCO₃ | E01025192, E01025193, E01025194 | Yorkshire Water 2026 edition |
Descriptions such as very soft, soft, moderately hard, hard, very hard are the water industry scale: very soft below 75, soft 75–125, moderately hard 125–250, hard 250–375, very hard above 375 mg/l. Your supplier may use a different scale for the same number.
Contains Yorkshire Water drinking water quality data, via Stream, licensed under CC BY 4.0. Edition 2026, published 1 January 2026. Yorkshire Water publishes this as mg/l without naming the species. We read it as calcium carbonate because the determinand is Hardness total and the dataset contains no calcium determinand. Evidence: determinand "Hardness total"; DWI code "HARD T"; no calcium determinand published in the dataset.
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 BB 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 BB area?
There are 13 BB postcode districts, running from BB1 to BB18, and they contain 13,608 live postcodes across 74 sectors.
What towns does the BB postcode area cover?
BB covers Blackburn, Burnley, Church, Nelson, Rawtenstall and Clitheroe. The area takes its name from Blackburn, and each district is listed with its settlement in the table on this page.
Which water company supplies BB postcodes?
United Utilities supplies all 13 BB 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 BB1 and BB2 both say Blackburn?
BB1 and BB2 all serve Blackburn, 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 BB postcode map?
Yes. This page offers the BB 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 the BB area called Blackburn when it covers Church?
BB takes its letters from Blackburn, where the sorting office that served the area was based when the code was allocated. Church is the largest settlement in the area today, in BB5, but the area code follows the historic sorting geography rather than current population.
Which councils cover the BB postcode area?
BB reaches into Lancashire and Blackburn with Darwen. A postcode area is not a council area: they were drawn for different purposes and a single district can sit across a council boundary, so your postcode does not tell you which authority you pay.