Got the wrong bill from Severn Trent or Hafren Dyfrdwy? Here is how to fix it.
This guide explains who Severn Trent is, the difference between Severn Trent Water and its Welsh sister company Hafren Dyfrdwy, the Guaranteed Standards Scheme that covers all UK water customers, the £2 million pollution fine they got in 2024, and how to send a proper complaint letter by Royal Mail.
About Severn Trent Water Limited
Severn Trent is the UK's second biggest water and sewage company by customer numbers. It serves around 4.6 million households and businesses. The service area covers "the heart of the UK" — from the Bristol Channel up to the Humber, and from North and mid-Wales across to the East Midlands. Severn Trent Water supplies 2 billion litres of drinking water every day and treats 3.1 billion litres of waste water. The legal name of the main operating company is Severn Trent Water Limited (Companies House number 02366686). The head office is at Severn Trent Centre, 2 St John's Street, Coventry CV1 2LZ.
Severn Trent is owned by its UK-listed parent company, Severn Trent plc. Severn Trent plc has been listed on the London Stock Exchange (ticker SVT) since the water industry was privatised in 1989. It is also a member of the FTSE 100 — the 100 biggest UK listed companies. This makes Severn Trent's ownership very different from Thames Water (which is privately owned by pension funds and sovereign wealth funds). Public listing means Severn Trent has to be more open about its finances. Revenue in 2025 was £2.43 billion. Net income was £229.4 million. Severn Trent has around 9,539 employees. The CEO is Liv Garfield — one of the few women running a FTSE 100 company. The Chair is Christine Hodgson.
Severn Trent does not just serve England. In 2017, Severn Trent bought Dee Valley Water (a smaller water company serving Wrexham and the Welsh borders). In July 2018, Dee Valley was renamed Hafren Dyfrdwy Cyfyngedig (the Welsh words for "Severn Dee Limited"). Today, Hafren Dyfrdwy is a separate legal entity that serves customers in Wrexham, parts of Denbighshire and Flintshire, and northern Powys. So if you live in north or mid Wales, your water contract is probably with Hafren Dyfrdwy, NOT Severn Trent Water. The two companies share the same UK parent but are separate legal entities with separate licences from Ofwat.
Registered office
Severn Trent Water LimitedSevern Trent Centre, 2 St John's Street
Coventry, West Midlands
CV1 2LZ
United Kingdom
Companies House number: 02366686 · Incorporated: 1 April 1989 · Parent: Severn Trent plc (LSE: SVT, FTSE 100) — also owns Hafren Dyfrdwy Cyfyngedig (Companies House 02784615, formerly Dee Valley Water plc, renamed July 2018) · Regulator: Ofwat (Water Services Regulation Authority) · Ombudsman scheme: WATRS (Water Redress Scheme), run by CEDR
Group structure
Severn Trent plc (parent)
This is the publicly-listed parent company. Listed on the London Stock Exchange under the ticker SVT. A FTSE 100 member — one of the 100 biggest UK listed companies. Privatised in 1989 along with the rest of the water industry. Headquartered in Coventry. The board includes CEO Liv Garfield (in post for many years) and Chair Christine Hodgson.
LSE ticker SVT. FTSE 100 member.Severn Trent Water Limited (the main operating company)
This is the company that holds the Ofwat water and sewage licence for the Midlands service area. Companies House number 02366686. Registered office at Severn Trent Centre, 2 St John's Street, Coventry CV1 2LZ. This is the legal entity that holds your customer contract if you live in Severn Trent's English service area, and that you would sue or formally complain to.
Companies House 02366686. Ofwat-licensed.Hafren Dyfrdwy Cyfyngedig (the Welsh operating company)
This is a separate operating company under the same Severn Trent plc parent. Hafren Dyfrdwy holds its own Ofwat licence for the Welsh service area (Wrexham, parts of Denbighshire and Flintshire, northern Powys). Previously Dee Valley Water plc, acquired by Severn Trent in February 2017 and renamed Hafren Dyfrdwy on 1 July 2018. Headquartered at Packsaddle, Rhostyllen, Wrexham LL14 4EH. If you are a customer in this area, your contract is with Hafren Dyfrdwy, NOT Severn Trent Water.
Companies House 02784615. The Welsh subsidiary.Water Plus (the non-household retail JV)
Water Plus is a 50/50 joint venture between Severn Trent and United Utilities, set up in June 2016 ahead of water market deregulation. It provides retail services for non-household (business) customers across England. If you run a business and your water bills come from "Water Plus", your contract is with this joint venture, not directly with Severn Trent.
Common reasons your Severn Trent Water Limited bill might be wrong
- 1You are being billed by the wrong company. If you live in Wrexham or the Welsh borders, your bill should come from Hafren Dyfrdwy, NOT Severn Trent. If you are getting both bills, or the wrong one, write a letter clarifying your address and demand the billing be sorted out.
- 2A new water meter installation shot your bill up. Severn Trent has been installing meters across the Midlands. Some customers move from a fixed "rateable value" bill to a metered bill that is much higher. The first metered bills can be wrong because the system needs time to settle.
- 3Your bill is based on estimates and the reads do not look right. Like energy bills, water bills can be based on estimates if a meter reading was not possible. If the estimate looks way off, ask for a manual reading and a re-calculation.
- 4You qualify for a social tariff but are not getting it. Severn Trent runs the "Big Difference" scheme (giving up to 90% discount on the bill) and is part of the national WaterSure scheme. Hafren Dyfrdwy runs the "HelpU" scheme. If you should be on one of these but are paying full price, demand the discount.
- 5You did not get a Guaranteed Standards Scheme payment after a service failure. Severn Trent and Hafren Dyfrdwy both have to pay automatic compensation when standards are not met. See the dedicated rules block below.
- 6You were charged for sewerage when your property does not connect to the main sewer. Some properties (especially rural ones in Severn Trent's area) have septic tanks or private drainage. If your property is not connected to the public sewer, you should not be charged for sewerage services.
The energy billing rules that protect you
| Rule | What it means | Source |
|---|---|---|
| Guaranteed Standards Scheme | If your water supply or sewerage service falls below set standards (low pressure, supply cuts, missed appointments), the water company has to pay you compensation. | Water Industry Act 1991 s.38; Water Supply and Sewerage Services (Customer Service Standards) Regulations 2008. |
| Maximum reasonable charges | Ofwat sets the maximum amounts water companies can charge each year. | Water Industry Act 1991 s.143. |
| Free help from CCW | The Consumer Council for Water (CCW) is the official advocate for water customers. | Water Industry Act 1991 s.27A. |
Severn Trent's 4-star rating and the £2 million 2024 fine
Severn Trent has a paradoxical regulatory record. In 2024, the Environment Agency gave Severn Trent a 4-star rating — the maximum possible. Only three of the 11 UK water and sewage companies achieved this in 2024 (the others were Wessex Water and United Utilities). This means Severn Trent's overall environmental performance was, by the regulator's measure, among the best in the country.
BUT on 19 February 2024, just months before that rating was confirmed, Severn Trent Water was fined £2.072 million at Cannock Magistrates' Court for "reckless" pollution at Strongford Sewage Treatment Works in Staffordshire. The court heard that between November 2019 and February 2020, around 260 million litres of raw sewage (the equivalent of 10 Olympic-sized swimming pools) was illegally discharged after pumps failed and Severn Trent failed to have a proper contingency plan. The court called the failure "reckless". The Environment Secretary at the time, Robbie Moore, said no one should profit from illegal pollution. In August 2024, Ofwat also opened a separate enforcement case against Severn Trent as part of its sector-wide wastewater investigation.
What this means for you: a 4-star rating does NOT mean Severn Trent or Hafren Dyfrdwy is immune from making mistakes. If you have had a service failure (interrupted supply, sewer flooding, low pressure, missed appointment), the Guaranteed Standards Scheme still applies and you can still claim. The fact that Severn Trent was specifically fined for failing to maintain contingency plans makes claims about ongoing operational failures (especially around storm overflows and sewer flooding) stronger.
Your rights
Water Industry Act 1991
This is the main law that governs the UK water industry. It sets out Severn Trent's and Hafren Dyfrdwy's duties (to supply wholesome water, to handle sewage properly, to be reasonable about prices), Ofwat's powers as the regulator, and your rights as a customer. Most of the other water rules sit underneath this Act.
Guaranteed Standards Scheme (Water Industry Act 1991 section 38)
This is the rule that gives you automatic compensation if Severn Trent or Hafren Dyfrdwy falls below set service standards. Specific failures that trigger payments include: water supply lost for more than 24 hours, low water pressure (lower than 7 metres static head for an hour), missed appointments, late reply to written complaints, and sewer flooding inside your home (£1,000+ compensation). The detailed rules are in the Water Supply and Sewerage Services (Customer Service Standards) Regulations 2008.
Water Industry Act 1991 section 27A (Consumer Council for Water)
This section created the Consumer Council for Water (CCW). CCW is the official, statutory body that represents water customers across England and Wales. CCW is free, independent of Ofwat, and free to use. The CCW route is the natural escalation step if Severn Trent or Hafren Dyfrdwy does not resolve your complaint.
Water Supply and Sewerage Services (Customer Service Standards) Regulations 2008
These are the detailed rules under the Water Industry Act 1991 that set out the specific compensation amounts under the Guaranteed Standards Scheme. They cover service standards like supply interruptions, low pressure, appointment management, complaint responses, and sewer flooding.
Consumer Rights Act 2015, sections 49 and 51
This is the general consumer law that applies to all services in the UK, including water. Section 49 says services must be performed with reasonable care and skill. Section 51 says the price must be reasonable if it is not agreed in advance.
How long do you have to challenge a bill?
The Limitation Act 1980 gives you 6 years to bring a court claim about a contract dispute in England, Wales and Northern Ireland (5 years in Scotland). Water companies cannot generally recover bills for water used more than 6 years ago. For the Guaranteed Standards Scheme, claims should usually be made within 3 months of the failure.
Common Severn Trent Water Limited situations
You got a huge bill after a new water meter was installed
Severn Trent and Hafren Dyfrdwy have been pushing the switch from rateable-value bills to metered bills. Some customers find the new metered bill is much higher than the old fixed bill. Take a manual meter reading and check it against the bill. Also check the tariff (rate per cubic metre) is right. If you can show the meter readings or rates are wrong, write a letter demanding a re-calculation.
You had sewer flooding inside your home
Internal sewer flooding triggers a significant Guaranteed Standards Scheme payment (usually £1,000+ for internal flooding, with cleaning and damage costs separate). If Severn Trent did not pay automatically, write a letter giving the date of the flooding, what happened, photos if you have them, and demand the GSS payment under the Water Supply and Sewerage Services Regulations 2008. The February 2024 Strongford fine showed Severn Trent had been failing at sewage management — this strengthens your claim.
Your water supply was lost for over 24 hours
If Severn Trent or Hafren Dyfrdwy cut off your supply for more than 24 hours (and it was NOT properly planned with notice), GSS compensation should be paid automatically. Write a letter giving the dates, the reason if known, and demand the payment under the 2008 Regulations.
You think you qualify for "Big Difference" or "HelpU" but are paying full price
Severn Trent's social tariff is called the Big Difference scheme — it can give up to 90% off your bill if you are on a low income. Hafren Dyfrdwy's equivalent is called HelpU. Check eligibility. If you should have been on a social tariff for months or years and were not, you can ask the company to apply the discount retrospectively.
You are being billed by the wrong company
If you live in the Wrexham area, your bills should come from Hafren Dyfrdwy. If you live in the Midlands or core English service area, your bills should come from Severn Trent Water. If you have moved house between the two areas and your bills are wrong, or if you are being billed by both, write to the WRONG company first to close the account, then to the right company to confirm setup.
A previous occupant's debt was added to your account
If you moved into a new property, debts run up by previous occupants are NOT yours. You only owe Severn Trent or Hafren Dyfrdwy for water used since you moved in. Send a letter with your tenancy agreement start date (or completion date if you bought the property) and demand the historical balance be removed.
Severn Trent or Hafren Dyfrdwy is ignoring your complaint
After 8 weeks of unresolved complaint or a final response, take the case to the Consumer Council for Water (CCW) free of charge. CCW is the statutory consumer body and Severn Trent / Hafren Dyfrdwy have to engage with them. If CCW cannot resolve it, you can then escalate to WATRS (the Water Redress Scheme), which makes binding decisions.
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Frequently asked questions
I live near the Welsh border. Am I a Severn Trent or Hafren Dyfrdwy customer?
It depends on your exact address. Hafren Dyfrdwy serves Wrexham, parts of Denbighshire, parts of Flintshire, and northern Powys. Severn Trent Water serves everywhere else in the Severn Trent service area. The legal entity name will be on the bottom of your bill (Severn Trent Water Limited OR Hafren Dyfrdwy Cyfyngedig). If you are not sure, call either company or check their postcode finders online.
How is Severn Trent different from Thames Water?
Big differences. Severn Trent plc is listed on the London Stock Exchange (FTSE 100 member), so it is publicly traded with thousands of small shareholders. Thames Water is owned by a private consortium of pension funds and sovereign wealth funds through Kemble Water Holdings. Severn Trent is in good financial shape and profitable. Thames Water has £19–20 billion of debt and is at risk of special administration. But Severn Trent has still been fined for pollution (£2 million in February 2024) — so it is not perfect.
What is the Guaranteed Standards Scheme?
It is a set of legally binding service standards that every UK water company has to follow. The standards are set out in the Water Supply and Sewerage Services (Customer Service Standards) Regulations 2008, made under the Water Industry Act 1991. If Severn Trent or Hafren Dyfrdwy falls below the standards (interrupted supply, low pressure, missed appointments, late complaint responses, internal sewer flooding), they have to pay automatic compensation. Amounts range from around £25 for a missed appointment to over £1,000 for internal sewer flooding.
What was the £2 million Severn Trent fine in 2024 about?
On 19 February 2024 at Cannock Magistrates' Court, Severn Trent Water was fined £2.072 million for "reckless" pollution at Strongford Sewage Treatment Works in Staffordshire. Between November 2019 and February 2020, around 260 million litres of raw sewage (10 Olympic-sized swimming pools' worth) was illegally discharged after pumps failed and Severn Trent did not have a proper contingency plan. The court called the failure "reckless".
How do I claim under the Guaranteed Standards Scheme?
Severn Trent and Hafren Dyfrdwy are supposed to pay GSS compensation automatically. If they did not, write a letter giving the date and nature of the failure (supply lost, missed appointment, sewer flooding, etc), quote the Water Supply and Sewerage Services (Customer Service Standards) Regulations 2008, and demand the payment. Most claims should be made within 3 months of the failure.
What is the Big Difference scheme?
It is Severn Trent's social tariff scheme for low-income customers. The scheme can give up to 90% off your bill (so a £400 annual bill could fall to £40). To qualify, your household income usually has to be below a threshold. Some households on certain benefits qualify automatically. The Hafren Dyfrdwy equivalent is called HelpU. If you think you should be on one of these schemes but are paying full price, apply now and ask the company to backdate the discount.
What is the difference between CCW and WATRS?
CCW (Consumer Council for Water) is the statutory consumer body created by section 27A of the Water Industry Act 1991. CCW represents water customers across England and Wales. CCW is free and helps you push complaints, but CCW does NOT make binding decisions. WATRS (Water Redress Scheme) is the binding adjudication body, run by CEDR. WATRS does make decisions that are binding on Severn Trent or Hafren Dyfrdwy. The escalation route is: water company → CCW → WATRS.
Severn Trent has a 4-star rating. Why should I bother complaining?
Because the rating measures overall environmental performance, not your specific bill or service. Even highly-rated water companies make mistakes on individual bills, miss appointments, fail to respond to complaints, or have local pressure problems. The Guaranteed Standards Scheme applies regardless of the company's overall rating. And the 2024 £2 million Strongford fine shows that even a 4-star Severn Trent can have serious operational failures.
Free help and what to do next
Consumer Council for Water (CCW)
The official, free, statutory consumer body for water customers in England and Wales. Created by section 27A of the Water Industry Act 1991. CCW helps you push a complaint with Severn Trent or Hafren Dyfrdwy and can give expert advice. Not binding but the companies have to engage with them. Helpline: 0300 034 2222.
Visit website →WATRS (Water Redress Scheme)
The binding adjudication body for water customer disputes in England and Wales. Run by CEDR (Centre for Effective Dispute Resolution). After CCW or after the company gives a final response, you can escalate to WATRS. Decisions are binding on Severn Trent or Hafren Dyfrdwy (up to a financial cap). Free for customers.
Visit website →Ofwat (the regulator)
The Water Services Regulation Authority. Does not handle individual complaints (that is CCW and WATRS) but enforces the licence conditions. Ofwat opened an enforcement case against Severn Trent in August 2024 as part of the wider sector wastewater investigation. Worth reporting persistent bad behaviour.
Visit website →Money Claim Online (MCOL)
The online court service for England and Wales. Use this if Severn Trent or Hafren Dyfrdwy refuses to follow a WATRS decision, or to sue them directly. You have 6 years from the date of the disputed bill to sue (5 in Scotland).
Visit website →Ready to challenge your Severn Trent Water Limited bill?
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