Battle · 10 companies
Water companies
In the flow, or in deep water?
United Utilities leads on pre-tax profit and profit margin; Thames Water on turnover; Southern Water on growth; Severn Trent on net assets. Thames Water is the biggest by turnover at £3,757m, against £2,616m at United Utilities. United Utilities keeps the most of every £100 it takes, £29.37 as pre-tax profit.
The year ends are up to 15 months apart, so this compares each company's most recent filing rather than the same twelve months. Thames Water, Severn Trent, United Utilities, Anglian Water and Northumbrian Water file group accounts that include subsidiaries; Yorkshire Water, Southern Water, Wessex Water, South West Water and Welsh Water file for a single company, which flatters the groups on size.
Accounts compared: Thames Water to Mar 2026 · Severn Trent to Mar 2026 · United Utilities to Mar 2026 · Anglian Water to Mar 2026 · Yorkshire Water to Mar 2026 · Southern Water to Mar 2026 · Wessex Water to Jun 2026 · South West Water to Mar 2026 · Welsh Water to Mar 2026 · Northumbrian Water to Mar 2025
The Numbers
| # | Company | Turnover | Change | Pre-tax profit | Margin | Employees | Pay per head | Turnover per head | Net assets | Bank and cash | Accounts to | Basis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Thames WaterThames Water Utilities Limited | £3,757m | +37.2% | £226m | 6.0% | 8,472 | £71,000 | £443,000 | £342m | £557m | Mar 2026 | Group |
| 2 | United UtilitiesUnited Utilities Water Limited | £2,616m | +22.3% | £768m | 29.4% | 6,678 | £38,000 | £392,000 | £1,761m | £1,556m | Mar 2026 | Group |
| 3 | Severn TrentSevern Trent Water Limited | £2,588m | +16.9% | £589m | 22.8% | 9,805 | £62,000 | £264,000 | £3,308m | £758m | Mar 2026 | Group |
| 4 | Anglian WaterAnglian Water Services Limited | £2,103m | +20.2% | £125m | 5.9% | 6,053 | £67,000 | £347,000 | £2,593m | £553m | Mar 2026 | Group |
| 5 | Yorkshire WaterYorkshire Water Services Limited | £1,640m | +26.2% | £114m | 6.9% | 4,481 | £61,000 | £366,000 | £1,361m | £571m | Mar 2026 | Single company |
| 6 | Southern WaterSouthern Water Services Limited | £1,443m | +45.4% | -£139m | -9.7% | 3,109 | £70,000 | £464,000 | £1,610m | £1,159m | Mar 2026 | Single company |
| 7 | Welsh WaterDWR Cymru Cyfyngedig | £1,170m | +27.7% | -£88m | -7.5% | 4,056 | £55,000 | £288,000 | £1,506m | £572m | Mar 2026 | Single company |
| 8 | Northumbrian WaterNorthumbrian Water Limited | £1,017m | +10.7% | £114m | 11.2% | 3,505 | £52,000 | £290,000 | £165m | £165m | Mar 2025 | Group |
| 9 | South West WaterSouth West Water Limited | £939m | +27.1% | £125m | 13.3% | 2,695 | £56,000 | £348,000 | £1,084m | £250m | Mar 2026 | Single company |
| 10 | Wessex WaterWessex Water Services Limited | £803m | +16.2% | £96m | 11.9% | 2,768 | £61,000 | £290,000 | £587m | £1.9m | Jun 2026 | Single company |
Ranked by turnover. Click any column to sort. The leader on each measure is highlighted. Movements are against each company's own prior year. Pre-tax profit is filed except where marked (est.).
Category winners
Biggest by turnover
Thames Water
£3,757m
Most pre-tax profit
United Utilities
£768m
Highest profit margin
United Utilities
29.4%
Fastest-growing turnover
Southern Water
+45.4%
Biggest employer
Severn Trent
9,805 staff
Highest pay per head
Thames Water
£71,000
Most turnover per head
Southern Water
£464,000
Largest net assets
Severn Trent
£3,308m
Most cash
United Utilities
£1,556m
The Takeaway
- United Utilities converts the most of its turnover. Of every £100, £29.37 reaches pre-tax profit, against a loss of £9.66 at Southern Water.
- Thames Water is the largest on the top line, £3,757m of turnover, 1.4x United Utilities's £2,616m.
- Southern Water is growing fastest, turnover +45.4% on its own prior year.
- Severn Trent is the biggest employer with 9,805 people; Thames Water pays the most per head, an average staff cost of about £71,000.
- Severn Trent has the largest balance sheet, net assets of £3,308m, while United Utilities holds the most cash at £1,556m.
Who keeps the most of every £100 of sales?
United Utilities keeps the most: £29.37 of every £100 of turnover becomes pre-tax profit. Southern Water does worst, losing £9.66.
Financing bites hardest at Southern Water: £29.70 of every £100 goes on interest.
Every profit figure here is the one the company filed.
The chart splits each company's turnover into £100: what goes on people, on interest and on everything else, and what is left as profit.
Out of every £100 of turnover
Each bar is £100 of that company's own turnover, so companies of any size compare on one scale; the figures are pounds out of each £100, not millions. Companies run from the best margin to the worst. Payroll is staff costs, financing is interest paid, other running costs are everything else, and profit is pre-tax profit, filed or estimated as marked in the table. A loss is not an extra cost: it is the part of the costs that runs past the £100 line, marked with a red bracket. Hover over any segment for its figure.
Who is the biggest, and does the comparison hold?
By turnover the order is Thames Water (£3,757m), United Utilities (£2,616m), Severn Trent (£2,588m), Anglian Water (£2,103m), Yorkshire Water (£1,640m), Southern Water (£1,443m), Welsh Water (£1,170m), Northumbrian Water (£1,017m), South West Water (£939m), Wessex Water (£803m).
By headcount, Severn Trent leads with 9,805 employees.
The comparison holds with the dates stated plainly: Thames Water to Mar 2026, Severn Trent to Mar 2026, United Utilities to Mar 2026, Anglian Water to Mar 2026, Yorkshire Water to Mar 2026, Southern Water to Mar 2026, Wessex Water to Jun 2026, South West Water to Mar 2026, Welsh Water to Mar 2026, Northumbrian Water to Mar 2025. The bases differ: group accounts include the businesses a company owns, single-company accounts do not.
Turnover on the latest filing
Who is growing fastest?
Southern Water grew fastest, turnover +45.4% on its own prior year, ahead of Thames Water (+37.2%), Welsh Water (+27.7%), South West Water (+27.1%), Yorkshire Water (+26.2%), United Utilities (+22.3%), Anglian Water (+20.2%), Severn Trent (+16.9%), Wessex Water (+16.2%), Northumbrian Water (+10.7%).
Turnover change on each company's own prior year
Who employs the most, who pays the most, and who brings in the most per head?
Severn Trent employs the most, 9,805 people, against 8,472 at Thames Water.
Thames Water has the highest average staff cost, about £71,000 a head; United Utilities the lowest, about £38,000.
Southern Water brings in the most turnover per employee, about £464,000, against £264,000 at Severn Trent. It says as much about the business model as the workforce: a marketplace or a wholesaler needs far fewer people per pound than a restaurant or a gym.
Thames Water
8,472
employees, about £71,000 pay a head, £443,000 turnover a head, +8.3% on the year
Severn Trent
9,805
employees, about £62,000 pay a head, £264,000 turnover a head, +11.9% on the year
United Utilities
6,678
employees, about £38,000 pay a head, £392,000 turnover a head, +10.2% on the year
Anglian Water
6,053
employees, about £67,000 pay a head, £347,000 turnover a head, +3.0% on the year
Yorkshire Water
4,481
employees, about £61,000 pay a head, £366,000 turnover a head, +15.6% on the year
Southern Water
3,109
employees, about £70,000 pay a head, £464,000 turnover a head, +13.4% on the year
Wessex Water
2,768
employees, about £61,000 pay a head, £290,000 turnover a head, -4.2% on the year
South West Water
2,695
employees, about £56,000 pay a head, £348,000 turnover a head, -3.0% on the year
Welsh Water
4,056
employees, about £55,000 pay a head, £288,000 turnover a head, +0.2% on the year
Northumbrian Water
3,505
employees, about £52,000 pay a head, £290,000 turnover a head, +7.2% on the year
Who owns each one?
Ownership as recorded on the Companies House register of people with significant control, in the bands the register uses.
Held by Thames Water Utilities Holdings Limited
A company recorded as a person with significant control. 7 outstanding charges on the register.
Who owns Thames Water →
Severn Trent Water Limited · 02366686Held by Severn Trent Draycote Limited
A company recorded as a person with significant control.
Who owns Severn Trent →
United Utilities Water Limited · 02366678Held by United Utilities North West Limited
A company recorded as a person with significant control.
Who owns United Utilities →
Anglian Water Services Limited · 02366656Held by Anglian Water Services Uk Parent Co Limited
A company recorded as a person with significant control. 3 outstanding charges on the register.
Who owns Anglian Water →
Yorkshire Water Services Limited · 02366682Held by Yorkshire Water Services Holdings Limited
A company recorded as a person with significant control. 2 outstanding charges on the register.
Who owns Yorkshire Water →
Southern Water Services Limited · 02366670Held by Sws Holdings Limited
A company recorded as a person with significant control. 3 outstanding charges on the register.
Who owns Southern Water →
Wessex Water Services Limited · 02366648Held by Wessex Water Limited
A company recorded as a person with significant control.
Who owns Wessex Water →
South West Water Limited · 02366665Held by Pennon Group Plc
A company recorded as a person with significant control. 2 outstanding charges on the register.
Who owns South West Water →
DWR Cymru Cyfyngedig · 02366777Held by Dwr Cymru (Holdings) Limited
A company recorded as a person with significant control. 2 outstanding charges on the register.
Who owns Welsh Water →
Northumbrian Water Limited · 02366703Held by Northumbrian Water Group Limited
A company recorded as a person with significant control. 1 outstanding charge on the register.
Who owns Northumbrian Water →
What does the full ledger show?
| Measure | Thames Water | Severn Trent | United Utilities | Anglian Water | Yorkshire Water | Southern Water | Wessex Water | South West Water | Welsh Water | Northumbrian Water |
|---|---|---|---|---|---|---|---|---|---|---|
| Registered name | THAMES WATER UTILITIES LIMITED | SEVERN TRENT WATER LIMITED | UNITED UTILITIES WATER LIMITED | ANGLIAN WATER SERVICES LIMITED | YORKSHIRE WATER SERVICES LIMITED | SOUTHERN WATER SERVICES LIMITED | WESSEX WATER SERVICES LIMITED | SOUTH WEST WATER LIMITED | DWR CYMRU CYFYNGEDIG | NORTHUMBRIAN WATER LIMITED |
| Company number | 02366661 | 02366686 | 02366678 | 02366656 | 02366682 | 02366670 | 02366648 | 02366665 | 02366777 | 02366703 |
| Incorporated | 1989 | 1989 | 1989 | 1989 | 1989 | 1989 | 1989 | 1989 | 1989 | 1989 |
| Accounts filed | 3 September 2026 | 10 August 2026 | 25 July 2026 | 1 September 2026 | 2 September 2026 | 10 September 2026 | 2 October 2026 | 7 August 2026 | 16 September 2026 | 8 September 2025 |
| Turnover, prior year | £2,738m | £2,214m | £2,139m | £1,749m | £1,299m | £993m | £691m | £739m | £916m | £919m |
| Pre-tax profit, prior year | -£1,647m | £398m | £332m | £189m | £430m | -£89m | £32m | -£61m | -£152m | -£1.2m |
| Staff costs | £605m | £606m | £252m | £406m | £274m | £217m | £168m | £152m | £225m | £182m |
| Payroll share of turnover | 16.1% | 23.4% | 9.6% | 19.3% | 16.7% | 15.0% | 20.9% | 16.2% | 19.2% | 17.9% |
| Employees, prior year | 7,824 | 8,763 | 6,060 | 5,874 | 3,876 | 2,741 | 2,890 | 2,777 | 4,047 | 3,270 |
| Dividends paid | n/d | £150m | £245m | £75m | £85m | n/d | n/d | n/d | n/d | £40m |
| Charges outstanding | 7 | 0 | 0 | 3 | 2 | 3 | 0 | 2 | 2 | 1 |
A figure the filing does not disclose is shown as n/d; a zero in a filing is treated as not disclosed. Rounding: below £0.1m in thousands, £0.1m to £2m to one decimal place, above that to the nearest million.
Water companies: common questions
Who is the biggest of Thames Water, Severn Trent, United Utilities, Anglian Water, Yorkshire Water, Southern Water, Wessex Water, South West Water, Welsh Water or Northumbrian Water?
Thames Water, with turnover of £3,757m in the year to March 2026.
Which makes the most profit?
United Utilities: £768m pre-tax in the year to March 2026.
Which employs the most people?
Severn Trent, with 9,805 employees in its latest accounts.
Thames Water or Severn Trent: which is bigger?
Thames Water, with turnover of £3,757m against £2,588m at Severn Trent on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit. The full head to head is in the VS Series. Read the VS page →
Thames Water or United Utilities: which is bigger?
Thames Water, with turnover of £3,757m against £2,616m at United Utilities on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
Thames Water or Anglian Water: which is bigger?
Thames Water, with turnover of £3,757m against £2,103m at Anglian Water on their latest filings. On margin, Thames Water keeps more of each £100 as pre-tax profit.
Thames Water or Yorkshire Water: which is bigger?
Thames Water, with turnover of £3,757m against £1,640m at Yorkshire Water on their latest filings. On margin, Yorkshire Water keeps more of each £100 as pre-tax profit.
Thames Water or Southern Water: which is bigger?
Thames Water, with turnover of £3,757m against £1,443m at Southern Water on their latest filings. On margin, Thames Water keeps more of each £100 as pre-tax profit.
Thames Water or Wessex Water: which is bigger?
Thames Water, with turnover of £3,757m against £803m at Wessex Water on their latest filings. On margin, Wessex Water keeps more of each £100 as pre-tax profit.
Thames Water or South West Water: which is bigger?
Thames Water, with turnover of £3,757m against £939m at South West Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit. The full head to head is in the VS Series. Read the VS page →
Thames Water or Welsh Water: which is bigger?
Thames Water, with turnover of £3,757m against £1,170m at Welsh Water on their latest filings. On margin, Thames Water keeps more of each £100 as pre-tax profit.
Thames Water or Northumbrian Water: which is bigger?
Thames Water, with turnover of £3,757m against £1,017m at Northumbrian Water on their latest filings. On margin, Northumbrian Water keeps more of each £100 as pre-tax profit.
Severn Trent or United Utilities: which is bigger?
United Utilities, with turnover of £2,616m against £2,588m at Severn Trent on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
Severn Trent or Anglian Water: which is bigger?
Severn Trent, with turnover of £2,588m against £2,103m at Anglian Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
Severn Trent or Yorkshire Water: which is bigger?
Severn Trent, with turnover of £2,588m against £1,640m at Yorkshire Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
Severn Trent or Southern Water: which is bigger?
Severn Trent, with turnover of £2,588m against £1,443m at Southern Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
Severn Trent or Wessex Water: which is bigger?
Severn Trent, with turnover of £2,588m against £803m at Wessex Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
Severn Trent or South West Water: which is bigger?
Severn Trent, with turnover of £2,588m against £939m at South West Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
Severn Trent or Welsh Water: which is bigger?
Severn Trent, with turnover of £2,588m against £1,170m at Welsh Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
Severn Trent or Northumbrian Water: which is bigger?
Severn Trent, with turnover of £2,588m against £1,017m at Northumbrian Water on their latest filings. On margin, Severn Trent keeps more of each £100 as pre-tax profit.
United Utilities or Anglian Water: which is bigger?
United Utilities, with turnover of £2,616m against £2,103m at Anglian Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
United Utilities or Yorkshire Water: which is bigger?
United Utilities, with turnover of £2,616m against £1,640m at Yorkshire Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
United Utilities or Southern Water: which is bigger?
United Utilities, with turnover of £2,616m against £1,443m at Southern Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
United Utilities or Wessex Water: which is bigger?
United Utilities, with turnover of £2,616m against £803m at Wessex Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
United Utilities or South West Water: which is bigger?
United Utilities, with turnover of £2,616m against £939m at South West Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
United Utilities or Welsh Water: which is bigger?
United Utilities, with turnover of £2,616m against £1,170m at Welsh Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
United Utilities or Northumbrian Water: which is bigger?
United Utilities, with turnover of £2,616m against £1,017m at Northumbrian Water on their latest filings. On margin, United Utilities keeps more of each £100 as pre-tax profit.
Anglian Water or Yorkshire Water: which is bigger?
Anglian Water, with turnover of £2,103m against £1,640m at Yorkshire Water on their latest filings. On margin, Yorkshire Water keeps more of each £100 as pre-tax profit.
Anglian Water or Southern Water: which is bigger?
Anglian Water, with turnover of £2,103m against £1,443m at Southern Water on their latest filings. On margin, Anglian Water keeps more of each £100 as pre-tax profit.
Anglian Water or Wessex Water: which is bigger?
Anglian Water, with turnover of £2,103m against £803m at Wessex Water on their latest filings. On margin, Wessex Water keeps more of each £100 as pre-tax profit.
Anglian Water or South West Water: which is bigger?
Anglian Water, with turnover of £2,103m against £939m at South West Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit.
Anglian Water or Welsh Water: which is bigger?
Anglian Water, with turnover of £2,103m against £1,170m at Welsh Water on their latest filings. On margin, Anglian Water keeps more of each £100 as pre-tax profit.
Anglian Water or Northumbrian Water: which is bigger?
Anglian Water, with turnover of £2,103m against £1,017m at Northumbrian Water on their latest filings. On margin, Northumbrian Water keeps more of each £100 as pre-tax profit.
Yorkshire Water or Southern Water: which is bigger?
Yorkshire Water, with turnover of £1,640m against £1,443m at Southern Water on their latest filings. On margin, Yorkshire Water keeps more of each £100 as pre-tax profit.
Yorkshire Water or Wessex Water: which is bigger?
Yorkshire Water, with turnover of £1,640m against £803m at Wessex Water on their latest filings. On margin, Wessex Water keeps more of each £100 as pre-tax profit.
Yorkshire Water or South West Water: which is bigger?
Yorkshire Water, with turnover of £1,640m against £939m at South West Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit.
Yorkshire Water or Welsh Water: which is bigger?
Yorkshire Water, with turnover of £1,640m against £1,170m at Welsh Water on their latest filings. On margin, Yorkshire Water keeps more of each £100 as pre-tax profit.
Yorkshire Water or Northumbrian Water: which is bigger?
Yorkshire Water, with turnover of £1,640m against £1,017m at Northumbrian Water on their latest filings. On margin, Northumbrian Water keeps more of each £100 as pre-tax profit.
Southern Water or Wessex Water: which is bigger?
Southern Water, with turnover of £1,443m against £803m at Wessex Water on their latest filings. On margin, Wessex Water keeps more of each £100 as pre-tax profit.
Southern Water or South West Water: which is bigger?
Southern Water, with turnover of £1,443m against £939m at South West Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit.
Southern Water or Welsh Water: which is bigger?
Southern Water, with turnover of £1,443m against £1,170m at Welsh Water on their latest filings. On margin, Welsh Water keeps more of each £100 as pre-tax profit.
Southern Water or Northumbrian Water: which is bigger?
Southern Water, with turnover of £1,443m against £1,017m at Northumbrian Water on their latest filings. On margin, Northumbrian Water keeps more of each £100 as pre-tax profit.
Wessex Water or South West Water: which is bigger?
South West Water, with turnover of £939m against £803m at Wessex Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit.
Wessex Water or Welsh Water: which is bigger?
Welsh Water, with turnover of £1,170m against £803m at Wessex Water on their latest filings. On margin, Wessex Water keeps more of each £100 as pre-tax profit.
Wessex Water or Northumbrian Water: which is bigger?
Northumbrian Water, with turnover of £1,017m against £803m at Wessex Water on their latest filings. On margin, Wessex Water keeps more of each £100 as pre-tax profit.
South West Water or Welsh Water: which is bigger?
Welsh Water, with turnover of £1,170m against £939m at South West Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit.
South West Water or Northumbrian Water: which is bigger?
Northumbrian Water, with turnover of £1,017m against £939m at South West Water on their latest filings. On margin, South West Water keeps more of each £100 as pre-tax profit.
Welsh Water or Northumbrian Water: which is bigger?
Welsh Water, with turnover of £1,170m against £1,017m at Northumbrian Water on their latest filings. On margin, Northumbrian Water keeps more of each £100 as pre-tax profit.
Where do these figures come from?
Each company's latest accounts filed at Companies House. Each links to its full Spark Intel profile, which names the filing it comes from.
Deep dive: what story does Thames Water's money tell? →
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