BL postcode district map, Bolton
Supplier statuses last checked .
The BL postcode area covers 12 districts and 10,408 live postcodes, from BL0 to BL78. It is centred on Bolton and also covers Bury, Little Lever, Horwich, Farnworth and Westhoughton.
Districts here average 867 postcodes.
Where the BL districts sit
Where BL sits
It is administratively fragmented, reaching into Bolton, Bury, Lancashire and Rochdale and 1 other authority.
Water supply across BL
All 12 BL districts are supplied by United Utilities. That makes BL 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 BL.
The shape of the BL area
The districts are wildly uneven: BL1 holds 1,852 postcodes around Bolton and BL78 holds 5, a ratio of about 370 to one. They divide into 53 sectors.
The numbering is not continuous. BL runs up to 78 but has only 12 districts, so 67 numbers are unused:.
District by district: BL0 serves Ramsbottom, BL1 serves Bolton, BL2 serves Bolton, BL3 serves Little Lever, BL4 serves Farnworth, BL5 serves Westhoughton, BL6 serves Horwich, BL7 serves Bolton, BL8 serves Bury, BL9 serves Bury, BL11 serves Bolton and BL78 serves Farnworth.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: BL1, BL2, BL7 and BL11 all point at Bolton, BL4 and BL78 all point at Farnworth and BL8 and BL9 all point at Bury.
What borders BL
BL sits next to M (Manchester) to the south east, WN (Wigan) to the south west, OL (Oldham) to the east, BB (Blackburn) to the north and WA (Warrington) to the south.
Its neighbours run in 5 different directions, so BL is landlocked by other postcode areas on most sides.
BL districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| BL0 | Ramsbottom | United Utilities | No restrictions |
| BL1 | Bolton | United Utilities | No restrictions |
| BL2 | Bolton | United Utilities | No restrictions |
| BL3 | Little Lever | United Utilities | No restrictions |
| BL4 | Farnworth | United Utilities | No restrictions |
| BL5 | Westhoughton | United Utilities | No restrictions |
| BL6 | Horwich | United Utilities | No restrictions |
| BL7 | Bolton | United Utilities | No restrictions |
| BL8 | Bury | United Utilities | No restrictions |
| BL9 | Bury | United Utilities | No restrictions |
| BL11 | Bolton | United Utilities | No restrictions |
| BL78 | Farnworth | 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 BL
No water company covering BL publishes hardness figures as open data. The gap is named per district below so you know who to ask.
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 |
|---|---|---|---|---|
| BL0 | Not published by United Utilities. Check with your supplier. | |||
| BL1 | Not published by United Utilities. Check with your supplier. | |||
| BL2 | Not published by United Utilities. Check with your supplier. | |||
| BL3 | Not published by United Utilities. Check with your supplier. | |||
| BL4 | Not published by United Utilities. Check with your supplier. | |||
| BL5 | Not published by United Utilities. Check with your supplier. | |||
| BL6 | Not published by United Utilities. Check with your supplier. | |||
| BL7 | Not published by United Utilities. Check with your supplier. | |||
| BL8 | Not published by United Utilities. Check with your supplier. | |||
| BL9 | Not published by United Utilities. Check with your supplier. | |||
| BL11 | Not published by United Utilities. Check with your supplier. | |||
| BL78 | Not published by United Utilities. 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 BL 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 BL area?
There are 12 BL postcode districts, running from BL0 to BL78, and they contain 10,408 live postcodes across 53 sectors.
What towns does the BL postcode area cover?
BL covers Bolton, Bury, Little Lever, Horwich, Farnworth and Westhoughton. The area takes its name from Bolton, and each district is listed with its settlement in the table on this page.
Which water company supplies BL postcodes?
United Utilities supplies all 12 BL 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 BL1 and BL2 both say Bolton?
BL1, BL2, BL7 and BL11 all serve Bolton, 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 BL postcode map?
Yes. This page offers the BL 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.
Which councils cover the BL postcode area?
BL reaches into Bolton, Bury, Lancashire, Rochdale 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.
Why is there no BL10 postcode district?
BL10 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.