What a Thames Water leak allowance pays for
A Thames Water leak allowance is a possible adjustment to charges for water lost through a leak. It is not payment of a plumber’s invoice, compensation for disruption or a promise that damaged flooring will be replaced. Keep the water-account question separate from the physical repair and any insurance claim. You may need to pursue all three, but each has a different decision maker and evidence requirement.
Thames’ current application page says it reviews the claim after the leak is fixed and credits the account if approved. Its published conditions require prompt repair and supporting information. The fact that a plumber has attended is not itself confirmation that the leak has stopped or that an allowance has been accepted. An inspection invoice and a completed-repair invoice describe different events.
This guide is for the application stage: establishing the dates, assembling repair evidence, completing the supplier’s form and checking the resulting calculation. If you are still trying to decide whether a high bill indicates a leak, begin with our separate high-water-bill guide. Avoid writing “confirmed leak” on an application solely because the direct debit increased. A payment projection, an estimated meter reading and measured water loss are different pieces of information.
A useful starting folder contains the affected bill, account number, supplier messages, repair record and dated meter photographs. You do not need to invent a precise leak-start date if nobody knows it. Distinguish the first symptom, the first notification and the day the cause was confirmed.
Use the current form and record the two deadlines
The official application page checked on 20 September 2026 requires repair within four weeks of notification or identification and a claim within three months of repair, even before the next bill arrives. The downloadable form marked February 2024 instead says to submit within 90 days. Because those descriptions are not always identical calendar periods, use the earlier deadline and ask Thames to confirm any uncertainty rather than waiting for a new bill.
Make a small timeline before completing the application. Record the date you noticed something unusual, when Thames contacted you, when the plumber identified the leak, each repair attempt and the completion date. Where two dates differ, explain why. For example, noticing a high bill in July is not necessarily the same as locating an underground leak in August. It is Thames’ role to decide how the facts meet its conditions.
Save the version of the form and the confirmation of submission. If you use an online route, retain the reference and a copy of the information entered. If you post documents, keep copies and a record of sending them. Do not send your only original repair record and then rely on recalling its wording later.
If a deadline may already have passed, contact Thames promptly with the actual chronology and supporting correspondence. Do not alter dates or assume that a landlord’s delay automatically creates an exception. Ask what information it will consider and obtain the answer in writing where possible.
Sources: Thames Water: downloadable allowance form, February 2024
A repair record should explain what was actually fixed
The downloadable form asks for proof where a third party repaired the leak, such as an invoice or insurance documents. It also distinguishes an internal leak, an external private supply-pipe leak and work on Thames’ equipment. Those categories should follow the findings, not which box seems most likely to obtain an allowance.
For your own record, request a clear location and a short description of the failed component or pipe section. “Replaced leaking toilet inlet valve in upstairs bathroom” conveys more than “plumbing work”. For a buried pipe, the description could identify the area investigated and the repaired section without claiming knowledge of every metre of pipe. Ask the contractor to separate confirmed observations from suspected additional defects.
The completion record should also say whether further work remains. A temporary isolation that stops water loss but leaves a fixture unusable is not the same repair outcome as restoring normal service. If a temporary repair fails, report the recurrence and preserve both visit records. Do not quietly choose the earlier date as though the problem stayed resolved.
If Thames completed the repair, use its job reference and the information it requests instead of commissioning an unnecessary second invoice. If you repaired a minor fitting yourself, ask Thames which evidence it accepts. This article cannot promise that photographs or a parts receipt alone will satisfy the application. The aim is an accurate record, not paperwork manufactured after the event to imply a different job occurred.
| Record | What it should establish |
|---|---|
| Repair invoice | Actual location, work and completion date |
| Meter photographs | Correct meter, readings and dates |
| Supplier reference | Notification, submission and decision history |
| Revised statement | Accepted period, baseline and charge adjustments |
Post-repair readings need to describe ordinary use
The downloadable form asks for two readings after repair, at least 14 days apart. Record the actual meter display and date rather than converting a direct-debit amount into an assumed volume. Photograph the display where it is safe and accessible, and keep the same meter identifier with both readings. Do not lift unsafe covers, reach into flooded chambers or interfere with equipment to obtain a photograph.
Choose a period that reflects the household honestly. If everyone was away between the two readings, tell Thames; if relatives stayed or a garden project used substantial water, say so. The purpose is not to achieve the lowest possible result. It is to give the supplier a defensible picture of normal use after the loss has stopped.
An example illustrates the arithmetic without predicting an allowance. If a meter increases from 120 to 126 cubic metres over 15 days, that is six cubic metres over the period, or 0.4 cubic metres a day. This is a volume calculation, not evidence that 0.4 is the correct long-term baseline for every household. Record occupancy and unusual events alongside it.
If the meter is shared, inaccessible or apparently assigned to the wrong address, resolve that with Thames before treating its reading as proof about your home. A neat spreadsheet built from the wrong meter still produces the wrong account history. Ask how it wants readings supplied while an identification or access problem is being investigated.
Check the allowance calculation rather than just the credit amount
A credit should be read alongside the period and consumption assumptions used to calculate it. Ask which start and end dates were accepted, which readings were used, how ordinary use was estimated and what volume was treated as leakage. A short explanation of those inputs is more useful than a bare statement that the account has been adjusted.
Compare volumes before comparing pounds. A different tariff period, standing charge or previous balance can make two bills difficult to reconcile by looking only at their totals. Separate the original charged consumption, the corrected consumption and unrelated account entries. If your spreadsheet includes a payment twice or ignores an existing credit, it may create a disagreement that has nothing to do with the leak calculation.
One public Reddit account described a wrongly assigned meter, a later repaired leak and a disputed allowance. The poster subsequently reported that a review changed a large claimed balance into a small credit. That is an unverified individual account, not proof that other bills are wrong. Its useful lesson is to check meter identity and calculation inputs separately, rather than treating a single credit figure as the whole explanation.
Do not copy the poster’s decision to stop payments. Thames’ current application page says billing dates and payment arrangements continue while it considers the application. If payment is difficult or disputed, contact the supplier about the account and available support instead of assuming that submitting a form suspends collection automatically.
Sources: Public account: meter identity and disputed allowance
Ask separately about water and wastewater charges
A combined bill can contain more than a charge for clean water delivered. When reviewing a leak adjustment, ask Thames to identify which charge components it has changed and why. In particular, explain where the escaped water went if that is known: a toilet leaking into its bowl is a different physical situation from a supply pipe losing water into the ground.
Do not claim that every litre recorded during a leak failed to enter the sewer. Equally, do not assume an underground escape returned to the sewer just because wastewater is normally billed with water use. Provide the plumber’s actual findings and ask the supplier to explain the relevant treatment. If nobody established the destination, record that uncertainty rather than choosing the more favourable description.
This research did not establish a universal wastewater refund formula that can safely be applied to every Thames household claim. The current application route and the account’s charging arrangements should determine the answer. If another company supplies your clean water while Thames bills sewerage, identify both providers and ask which team needs the evidence. Sending a repair invoice to one organisation does not establish that the other account has been corrected.
When a revised statement arrives, compare water and wastewater lines individually. Record any remaining question against the relevant line rather than requesting the same total refund from two parties. You are asking for the correct treatment of the actual loss, not double recovery or an assumed standard percentage unrelated to the pipe’s location.
Be careful with internal leaks and conflicting published limits
Internal and external leaks are not interchangeable under the published material. Thames’ application form says an internal leakage allowance can be claimed once, while multiple external supply-pipe claims may be considered. The linked code also discusses circumstances in which an internal leak could reasonably have been known about. Do not describe a visible running toilet as an automatically eligible hidden leak.
There is another reason to confirm the current terms: the accessible February 2024 form describes a maximum two-year adjustment, while text in the currently linked leakage code refers to 12 months. This guide does not choose the larger limit as an entitlement. Ask Thames to state the period it is applying to your claim and provide the policy basis if those documents appear inconsistent.
In practice, keep the evidence of when the abnormal use started rather than stretching the claim to a maximum period merely because one document mentions it. A meter installation, household move or change in occupancy may limit the usefulness of earlier comparisons. If you have no comparable history, explain the gap and ask what baseline will be used.
An allowance refusal and a disagreement about the amount are also different questions. One concerns whether the criteria are met; the other concerns the calculation after eligibility. Ask which issue is outstanding so that your next response supplies relevant evidence rather than repeating the full history without addressing the stated reason.
Tenants should document delays and repeat failures
A tenant may pay the water account while relying on a landlord or agent to arrange access and repair. Contact the responsible property contact promptly and keep the dated report. Also tell Thames what is happening if its repair deadline is approaching. Neither conversation replaces the other: the agent needs to arrange work, while Thames needs an accurate account of the leakage and timing.
A 2026 public account described two plumbing visits to a leaking toilet, a temporary improvement and recurrence while the agency arranged further access. The eventual allowance outcome was not established. It highlights why “a plumber came” is an inadequate completion record. Note whether the leakage actually stopped, how that was checked and whether the fixture remained in normal use afterwards.
Keep correspondence factual. State when you reported the issue, the appointments offered, the work recorded and any continuing symptoms. Avoid attributing technical conclusions to a contractor who only inspected the outside of a concealed cistern. If tiles or boxing need opening, identify who can authorise that work so a further visit can progress.
The water-account holder should check how Thames wants an application submitted when repair documents name the landlord or managing agent. Supply relevant evidence with permission and avoid circulating unrelated personal information. This guide does not decide tenancy liability or guarantee an exception for delayed repairs; it helps preserve the facts needed for those separate decisions.
Sources: Public account: recurring toilet leak and agency delays
What to do when the application is incomplete or refused
Ask for the specific missing information or reason before paying for another visit. If the problem is a missing second reading, another plumber’s inspection may not address it. If the repair record is unclear, ask the original contractor for an accurate clarification. If continued consumption suggests a second leak, that is a new technical question rather than simply an administrative omission.
Respond with a short chronology and labelled attachments. Numbering a repair invoice, the two reading photographs and the relevant supplier message makes it easier to identify what each document establishes. Keep a copy of your reply and the reference. Avoid sending a large unstructured collection in which the actual completion date is difficult to find.
If you disagree with the decision, ask Thames to review it through its current complaints route and identify the particular point disputed. This may be meter assignment, accepted repair timing, normal-use baseline, eligible period or the treatment of a charge component. A focused question is easier to answer than a general statement that the bill seems excessive.
Do not commission retrospective wording that changes the job description to fit an application. An invoice can be clarified when incomplete, but it should still describe the work and findings honestly. A supplier’s rejection does not prove that the repair failed, just as an approved credit does not independently confirm that every plumbing defect has been resolved.
Finish the repair and the account as two separate tasks
Close the physical problem by checking normal use after the agreed repair and reporting any recurrence. Close the billing problem by retaining the submission reference, decision and revised statement. It is possible for one task to be complete while the other remains open: the pipe may be repaired before a credit is calculated, or an allowance may be processed while another unrelated fixture still wastes water.
For a repair enquiry, tell AK which leak has been identified, whether water is still escaping and whether access is restricted. If you need findings for Thames, mention that before the visit so the intended record is understood. AK can describe work it actually carries out; it cannot approve an allowance, change supplier deadlines or promise a particular credit.
AK’s ordinary plumbing pricing is £60 engineer attendance plus £160 per hour for agreed plumbing work, with no VAT added because AK is not VAT-registered. Specialist investigation needs its own agreed scope and quote. The attendance fee is not an included diagnosis, completed repair or supplier-accepted report. Confirm the relevant work before authorising it.
Keep your final account file even after the bill looks correct. If a later estimate or meter reassignment changes the statement, the original dates and readings will be easier to retrieve. The strongest application is not the longest narrative: it is a consistent set of facts linking an identified loss, an effective repair and a transparent calculation.