Go to the official application, not a third-party claim service
The starting point is Thames Water's household leak allowance page. It links to the leak-fixed notification and the allowance application. At the time of this guide's review, its application button opens an official allowance triage page. Begin there rather than using a bookmarked form copied from an old forum.
This guide helps you prepare the application. Leak Fix London does not operate the form, decide eligibility or issue credits. You do not need to book us to follow the official application route. If your leak has already been repaired and the evidence is complete, the next step is submitting it to Thames Water, not paying another contractor simply to complete paperwork.
For the broader question of what the allowance covers, use our Thames Water leak allowance guide. This page concentrates on the practical handover: making the dates, meter readings and repair record intelligible so that an assessor can follow what happened without several rounds of clarification.
Check that you are using the household process
Look at the bill before opening the form. Record the company which bills the account, the supply address and the account reference. A property supplied from Thames Water pipework is not necessarily using its direct household billing process. For a business account, the retailer shown on the bill is the starting point for the allowance enquiry.
CCW explains the retailer and wholesaler roles in its business water-market guidance. Do not copy a business allowance deadline into a household application, or vice versa. If a building has mixed residential and business use, ask the billing provider which process applies to the particular meter and account before relying on a general guide.
This matters in flats as well. The meter you can see might serve your dwelling, a landlord's supply or a communal area. Use the account and meter actually associated with the charges you are querying. If a managing agent handles the water bill, ask who must submit the application and what authority they need from you. Do not start several inconsistent applications for the same incident.
Put the key dates in one place before filling anything in
Thames Water's household page currently specifies repair within four weeks of notification or identification, and an allowance claim within three months of repair. It requests confirmation through the repairer's details and invoice, or its own repair job number, and excludes repairs completed under Section 75. Check the linked current terms when applying; approval is not automatic.
Make a small chronology using the records you actually have. Separate the date you first noticed an unusual bill from the date a leak was identified, and separate an investigation visit from the completed repair. If those dates happen to be the same, that is fine. If they differ, recording them accurately is better than squeezing them into a single convenient date.
| Event | Where to look for evidence | What to record |
|---|
| First notification | Letter, email, account message or call note | Date and reference, preserving the original wording |
| Leak identified | Plumber's report or your dated observation | What was confirmed, and by whom |
| Temporary isolation | Visit record or photograph | Whether supply was stopped without completing repair |
| Repair completed | Invoice and completion report | Actual work date, not merely invoice issue date |
| Post-repair readings | Meter photographs or account records | Reading, date and meter identity |
| Application submitted | Confirmation page or email | Reference and a copy of what was sent |
If a date is uncertain, identify the uncertainty. For example, a contractor may have attended on Tuesday and returned to repair on Thursday, while the invoice was issued on Friday. Ask for that distinction to be clarified in the paperwork. Do not change the facts to make the application look simpler.
Report the repair and request the allowance as separate actions
It is easy to tell Thames Water that a leak is fixed and assume the billing adjustment follows automatically. Its published process separates the repair notification from the allowance request. Keep a record of both submissions. If you only have an acknowledgement mentioning a fixed leak, check whether you have also completed the allowance stage.
Use one folder for the incident, containing the notification, report, invoice, meter records and correspondence. Name files so they are understandable without opening them: a date, the document type and the property reference are enough. Keep full originals for your records, while sending only the information needed for the application through the official channel.
If a contractor says it has notified Thames Water, ask what it submitted and for the acknowledgement. “We gave them the details” may mean a telephone conversation, a repair report or something unrelated to billing. Establish what has actually been done instead of duplicating it or assuming that the contractor submitted a claim on your behalf.
Complete account and property details consistently
Use the account holder's details as shown on the water bill. Where your correspondence address differs from the repaired property, keep the two clearly labelled. A landlord's home address is not the leak address, and an apartment number omitted from a block address can make an otherwise useful invoice difficult to match.
Check the account number character by character rather than relying on a phone's text recognition. Meter serial numbers, customer references and repair job numbers are different identifiers. Save each with its label. If you quote the wrong reference throughout an application, an assessor may not be able to connect your evidence to the account even when the property address is correct.
Where the form asks about occupancy, describe the actual circumstances. If the property was empty during part of the period, record when that changed. If a household grew or reduced in size, explain the dates separately. Those notes are useful context for understanding consumption; they are not an invitation to invent a “normal” usage figure which produces a larger credit.
Describe the leak in plain, verifiable language
Write where the repaired pipe or fitting was, what was wrong and what the contractor did. You do not need an elaborate technical diagnosis. “A leaking joint on the incoming pipe beneath the front path was replaced” is more useful than “major underground emergency” if that is what the repair report records.
Distinguish what you saw from what the contractor established. You may have seen a damp patch in the hall while the repair was actually to a supply pipe outside. The damp patch explains why the investigation began; the pipe location describes the confirmed fault. Both can be recorded without implying that the stain was directly above the leak.
A practical draft is: “The suspected leak was reported on [date]. [Repairer] inspected on [date] and identified [documented location and fault]. Repair was completed on [date]. The attached report describes the repair and the checks afterwards. Dated meter records are attached.” Replace every placeholder with facts or remove it; do not send this as a fictional statement of work.
If no one has located or repaired a leak yet, this is a preparation checklist, not a way to turn a high bill into proof of a completed repair. Start with the investigation. Our guide to a high water bill: leak or usage explains why a bill alone cannot identify which pipe or fitting is responsible.
Collect meter readings without losing the dates or units
The published paper form asks for two post-repair readings at least fourteen days apart, along with repair dates and evidence. Follow the instructions on the current application you use. If the deadline is close and a requested reading is not yet available, contact Thames Water promptly rather than silently waiting past the deadline.
For each reading, save the date, time and a clear photograph where it is safe to take one. Capture enough of the meter to establish its identity. Do not lift a heavy cover, reach into a flooded chamber or enter the road to obtain a photograph. If you cannot read the meter safely, use the official account or contact route for assistance.
Do not write down a different set of digits each time. Note which digits represent the units required by the application and follow the meter's reading instructions. Keep the unedited photograph even after transcribing the number. A later question about an apparent jump is easier to resolve when the original image is available.
If the meter was replaced during the leak period, record the change. A lower number on a new meter is not negative water use. Preserve the old closing reading, new opening reading and installation date if they are available. Do not subtract readings across two different meters as though they came from one uninterrupted register.
Check the arithmetic before you submit the readings
Use the difference between readings as a reasonableness check, not as your own guaranteed allowance calculation. For example, two readings of 510 and 514 cubic metres, fourteen days apart, represent four cubic metres across that period. That is roughly 286 litres per day. This is a hypothetical calculation to demonstrate the units, not a claim about what your household should use.
Now compare your arithmetic with the circumstances. Was everyone at home? Did a garden irrigation system run? Was building work using water? Was one date mistyped? You do not need to explain every litre, but large contradictions should be checked before submission. A reading mistakenly entered as 5,140 instead of 514 can overwhelm the useful evidence.
A post-repair average does not prove that every earlier excess unit was leakage. It provides a baseline for assessment alongside earlier records and occupancy. Keep your notes factual and let the water company explain its adjustment. If it uses a different comparison period, ask which readings and dates it used rather than assuming the whole decision is wrong.
Ask the repairer for a document naming the property, attendance date, completion date and work performed. Where detection and repair were separate appointments, retain both documents. A paid invoice establishes that a charge was made; a useful work description establishes what the charge concerned. You may need both to explain the incident clearly.
Look for vague wording before sending the evidence. “Plumbing works” may be accurate but unhelpful if several jobs were done that day. Ask for a factual clarification, not a rewritten story. The contractor can state which joint or pipe was repaired and whether any post-repair checks were made, provided those statements reflect the actual work.
If an insurer arranged the contractor, request the completion report through the claims handler or repair firm. Keep the claim reference separate from the water account number. An insurance document can explain who attended, but a letter saying a claim is open is not the same as a record that the water loss has stopped.
There is more on useful supporting material in our leak allowance evidence guide. Avoid ordering a second investigation solely because the first invoice is brief: first ask whether the existing contractor can provide the missing factual record.
You may not have a pre-leak meter photograph, particularly if the first warning came from a bill or a notification. Say what records are missing and provide the reliable ones you do hold. Never estimate a reading and present it as an actual meter observation. Label an estimate or a calculated figure explicitly if you are asked to provide one.
Likewise, do not invent a precise date when a concealed leak started. State when it was discovered and what evidence might indicate an earlier start. A consumption history may suggest a change during a particular interval without proving the exact day a pipe failed. That distinction should remain visible in the application.
If a form requires an answer you cannot accurately supply, contact the official support route and ask how to complete that field. Keep the question and answer with the application. This is better than entering a convenient placeholder that later conflicts with your invoice, tenancy dates or account history.
Save proof of submission and follow up on the actual question
Before sending, check the attachments open and are legible. A photograph of a folded invoice with the date cropped off may technically be an attachment but still fail to convey the evidence. Use a simple file format accepted by the official form. Save the completed submission or a copy of your answers where the process allows.
After sending, retain the acknowledgement and reference. If the confirmation only says that a message was received, do not describe it as approval. Where the company asks for more information, reply against the existing reference and identify which question each attachment answers. Creating a new application for every follow-up can make the record harder to follow.
Thames Water says billing and payment arrangements continue while it considers an allowance. If affordability is a problem, contact it to discuss the account rather than assuming an application suspends payments. Keep a payment-support discussion distinct from the evidence for the leak itself so that neither issue is lost in the correspondence.
When the decision arrives, retain the explanation and adjusted bill together. Ask for clarification if the credited period or reading comparison is unclear. A credit, a repair invoice and a goodwill payment are different things; do not combine them into one figure and assume it shows how the water allowance was calculated.
Keep the allowance separate from your repair booking
A household water allowance addresses eligible water charges. Your contractor's work and any insurance claim are separate arrangements. No repair company can promise Thames Water's decision. Be cautious about a quote justified mainly by a claim that “the water company will pay it all back” without a written basis from the company responsible for paying.
If the leak is still unresolved, send Leak Fix London the notice, symptoms and available meter readings. We can discuss finding and repairing a private supply-pipe leak, explain the proposed access and record what the investigation finds. The appropriate work depends on the property and confirmed fault.
Our rate is £150 per hour, with the total dependent on the time taken; see our pricing. If we do not find the leak, you do not pay for the time we spent looking. That commitment does not guarantee an allowance, waive unrelated repair costs or make us part of Thames Water. If the repair is already complete, use the official application links above and keep your evidence together.
