Why Thames Water may handle sewage but not your tap water
The company named on a water-related bill is not always the company supplying your tap water. Some London homes receive clean water and sewerage services from different providers. Use Water UK’s supplier finder and check the service shown on the account before reporting a leak, loss of supply or drainage problem.
Loyal Plumbers · Updated
Discuss your plumbing workStart with the service that has the problem
Describe whether the issue concerns water arriving at taps, wastewater leaving the building or water appearing somewhere unexpected. These are different starting points. A loss of cold-water supply usually belongs with the clean-water provider’s information, while a suspected public sewer problem belongs with the sewerage provider. A private plumbing fault may need a contractor as well.
Do not decide from the company name you recognise best. In some areas Thames Water handles wastewater while another company supplies drinking water. A combined bill can also conceal the distinction. If you are unsure, gather the address, postcode and a plain description of the symptom before contacting the relevant provider. That makes it easier to route the enquiry without unnecessary transfers.
Use the postcode finder and confirm the account details
Water UK’s official finder identifies water and wastewater providers by postcode. Use it as a starting point, then confirm the actual address and account where needed. A large block, new development or unusual arrangement may have additional management or supply details that deserve checking rather than being inferred from a neighbouring street.
Keep the provider names in the property file alongside the emergency contact routes. If you manage several homes, do not copy one property’s details across the whole portfolio. Supplier areas do not necessarily follow borough boundaries. A plumber’s London coverage and a utility’s supply territory are different things; a contractor working across London does not become the network operator at the address.
Read the bill by service rather than by total
Thames Water explains that customers can receive a combined bill or separate bills depending on who supplies their tap water. Look for the clean-water and wastewater elements and identify who issued each. A second bill is not automatically a duplicate charge, though an apparent account error should be queried with the company concerned.
For a rented home, ask the landlord or managing agent how the service is arranged if the occupier does not hold the direct account. Keep billing responsibility separate from physical pipe responsibility. The person who pays a bill is not automatically the person who may authorise work on every pipe serving the building. Our supply-pipe responsibility guide covers that additional question.
| Question | Where to start |
|---|---|
| Who supplies tap water? | Check the official supplier finder and the service shown on the account. |
| Who handles public sewerage? | Identify the wastewater provider; it may be a different company. |
| Who repairs a private fitting? | Establish the property arrangement and authorisation for a private plumbing visit. |
Route a clean-water problem with the right evidence
For no water or a suspected network leak, give the clean-water supplier the location, affected outlets and whether nearby properties are also affected, where that is already known. Use its current incident information rather than a different company’s map. A report on the wrong network may not reach the organisation that can investigate the supply.
If the supplier says the issue lies on private pipework, ask for its findings and any useful reference. Share those with the plumber or building manager. Do not describe a private plumbing appointment as a utility call-out. The contractor can assess the private installation within the agreed scope, while the supplier remains responsible for decisions about its own network and equipment.
Route drainage concerns without assuming every pipe is public
A slow sink, overflowing private gully and wider sewer flooding need different assessment. Identify the location and extent, and avoid opening covers or entering contaminated areas to prove the cause. Where the sewerage company is involved, keep its findings about the affected asset and any private section requiring attention.
Shared drainage can be particularly confusing because a pipe serving several properties may have a different responsibility position from a pipe serving one. The company name on a bill does not settle that route. Use the specific arrangement and current guidance. If a private drainage contractor attends, agree whether the work is investigation, clearance or repair and how findings will be reported if a public asset appears to be involved.
Keep the contacts useful for the next incident
Create a short record of the clean-water supplier, sewerage provider, account references and building-management contact. Add the known private isolation information where it has been safely established. Make it available to the people who actually manage the property, while protecting personal account details from unnecessary sharing.
For a Loyal Plumbers enquiry, provide the postcode, symptom and any supplier or managing-agent findings. Say which provider you have contacted and what it confirmed. This helps us discuss the private plumbing scope without sending you through the wrong utility process. We do not represent the water companies or replace their reporting channels; the useful result is a clear division of the work and the right contact for each part.
Common questions
- Does a Thames Water bill prove Thames supplies my tap water?
- Not always. Check which services the bill covers and use the official supplier finder to identify the clean-water and wastewater providers for the address.
- Should I report no water to the sewerage company?
- Use the clean-water supplier’s reporting and incident route. If the companies differ, a sewerage account alone does not identify the correct supply contact.
- Does the bill payer own every pipe?
- No. Billing arrangements and responsibility for physical pipework are separate questions. Establish the actual pipe route and property arrangement before authorising work.
Sources and further reading
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