BA postcode district map, Bath
Supplier statuses last checked .
The BA postcode area covers 19 districts and 15,524 live postcodes, from BA1 to BA22. It is centred on Bath and also covers Yeovil, Trowbridge, Midsomer Norton, Frome and Warminster.
Districts here average 817 postcodes.
Where the BA districts sit
1 district is plotted without a label where labels would overlap; every one is in the table below.
Where BA sits
It is administratively fragmented, reaching into Somerset, Wiltshire, Bath and North East Somerset and South Gloucestershire and 1 other authority.
Water supply across BA
All 19 BA districts are supplied by Wessex Water. That makes BA simple in a way many areas are not: one company, one set of rules, one status to check.
Wessex Water has a hosepipe ban in force from 18 August 2026, covering the whole of BA.
The shape of the BA area
BA2 is the largest district with 2,213 postcodes around Bath, and BA10 the smallest with 179. The area divides into 79 postcode sectors.
The numbering is not continuous. BA runs up to 22 but has only 19 districts, so 3 numbers are unused:.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: BA20, BA21 and BA22 all point at Yeovil and BA1 and BA2 all point at Bath.
What borders BA
BA sits next to BS (Bristol) to the north west, SP (Salisbury) to the east, DT (Dorchester) to the south, TA (Taunton) to the west and SN (Swindon) to the north east.
Its neighbours run in 5 different directions, so BA is landlocked by other postcode areas on most sides.
BA districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| BA1 | Bath | Wessex Water | Ban in force |
| BA2 | Bath | Wessex Water | Ban in force |
| BA3 | Midsomer Norton | Wessex Water | Ban in force |
| BA4 | Shepton Mallet | Wessex Water | Ban in force |
| BA5 | Wells | Wessex Water | Ban in force |
| BA6 | Glastonbury | Wessex Water | Ban in force |
| BA7 | Castle Cary | Wessex Water | Ban in force |
| BA8 | Stalbridge | Wessex Water | Ban in force |
| BA9 | Wincanton | Wessex Water | Ban in force |
| BA10 | Bruton | Wessex Water | Ban in force |
| BA11 | Frome | Wessex Water | Ban in force |
| BA12 | Warminster | Wessex Water | Ban in force |
| BA13 | Westbury | Wessex Water | Ban in force |
| BA14 | Trowbridge | Wessex Water | Ban in force |
| BA15 | Bradford-on-Avon | Wessex Water | Ban in force |
| BA16 | Street | Wessex Water | Ban in force |
| BA20 | Yeovil | Wessex Water | Ban in force |
| BA21 | Yeovil | Wessex Water | Ban in force |
| BA22 | Yeovil | Wessex 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 BA
Figures are in milligrams per litre as calcium carbonate, the unit UK water companies report in. 16 of 19 districts have a published figure.
| District | Hardness | As published | Supply zone | Published by |
|---|---|---|---|---|
| BA1 | 194.5–335.5 mg/l varies across this district | 299.2 mg/l as CaCO₃ | E01014370, E01014371, E01014372, E01014373 +31 more | Wessex Water 2022-2025 edition |
| BA2 | 246.3–325 mg/l varies across this district | 282.7 mg/l as CaCO₃ | E01014387, E01014388, E01014389, E01014390 +24 more | Wessex Water 2022-2025 edition |
| BA3 | 272 mg/l That is hard on the water industry scale. | 272 mg/l as CaCO₃ | E01014451 | Wessex Water 2022-2025 edition |
| BA4 | Not published by Wessex Water. Check with your supplier. | |||
| BA5 | Not published by Wessex Water. Check with your supplier. | |||
| BA6 | Not published by Wessex Water. Check with your supplier. | |||
| BA7 | 229.8–291.2 mg/l varies across this district | 269.3 mg/l as CaCO₃ | E01029166, E01029167, E01029168 | Wessex Water 2022-2025 edition |
| BA8 | 297.2 mg/l That is hard on the water industry scale. | 297.2 mg/l as CaCO₃ | E01029154, E01029155, E01029156 | Wessex Water 2022-2025 edition |
| BA9 | 299.1 mg/l That is hard on the water industry scale. | 299.1 mg/l as CaCO₃ | E01029221, E01029227, E01029228, E01029229 | Wessex Water 2022-2025 edition |
| BA10 | 301.6 mg/l That is hard on the water industry scale. | 301.6 mg/l as CaCO₃ | E01029157, E01029158 | Wessex Water 2022-2025 edition |
| BA11 | 263.8 mg/l That is hard on the water industry scale. | 263.8 mg/l as CaCO₃ | E01032051 | Wessex Water 2022-2025 edition |
| BA12 | 185.5–295.6 mg/l varies across this district | 269.9 mg/l as CaCO₃ | E01032076, E01032081, E01032082, E01032103 +11 more | Wessex Water 2022-2025 edition |
| BA13 | 246.7–312 mg/l varies across this district | 292.3 mg/l as CaCO₃ | E01032052, E01032054, E01032056, E01032115 +5 more | Wessex Water 2022-2025 edition |
| BA14 | 161–369.5 mg/l varies across this district | 287.1 mg/l as CaCO₃ | E01032053, E01032058, E01032078, E01032079 +24 more | Wessex Water 2022-2025 edition |
| BA15 | 344.1 mg/l That is hard on the water industry scale. | 344.1 mg/l as CaCO₃ | E01032045, E01032046, E01032047, E01032048 +6 more | Wessex Water 2022-2025 edition |
| BA16 | 157.4 mg/l That is moderately hard on the water industry scale. | 157.4 mg/l as CaCO₃ | E01029130 | Wessex Water 2022-2025 edition |
| BA20 | 106.3–364.9 mg/l varies across this district | 194.2 mg/l as CaCO₃ | E01020497, E01020530, E01020550, E01029159 +13 more | Wessex Water 2022-2025 edition |
| BA21 | 141–336.5 mg/l varies across this district | 253 mg/l as CaCO₃ | E01029161, E01029231, E01029232, E01029233 +11 more | Wessex Water 2022-2025 edition |
| BA22 | 118.5–243 mg/l varies across this district | 192.2 mg/l as CaCO₃ | E01029164, E01029165, E01029198 | Wessex Water 2022-2025 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 Wessex Water drinking water quality data, via Stream, licensed under CC BY 4.0. Edition 2022-2025, published 1 January 2025.
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 BA 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 BA area?
There are 19 BA postcode districts, running from BA1 to BA22, and they contain 15,524 live postcodes across 79 sectors.
What towns does the BA postcode area cover?
BA covers Bath, Yeovil, Trowbridge, Midsomer Norton, Frome and Warminster. The area takes its name from Bath, and each district is listed with its settlement in the table on this page.
Which water company supplies BA postcodes?
Wessex Water supplies all 19 BA 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 BA20 and BA21 both say Yeovil?
BA20, BA21 and BA22 all serve Yeovil, 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 BA postcode map?
Yes. This page offers the BA 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 BA postcode area?
BA reaches into Somerset, Wiltshire, Bath and North East Somerset, South Gloucestershire and Dorset. 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 BA19 postcode district?
BA19 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.