What an allowance actually is
Water companies are required by their licences to reimburse the cost of water lost through leakage by way of credits to your bill. That credit is the leakage allowance. It can apply to water supply charges and to wastewater charges, and it can only be claimed once the leak has been repaired. CCW puts the household position simply: when the leak has been repaired, your company should offer a leakage allowance for the lost water.
It is not automatic and it is not unconditional. Companies can refuse, for instance where the repair was not arranged within a reasonable timeframe the company specified, or where the leak was caused by the customer's own negligence. Each company has to publish how it handles leakage from household supply pipes, including how allowances are claimed, how they are applied and when they can be refused. Read your own supplier's policy, because the conditions differ.
The evidence pack
1. Proof the leak was repaired
This is the document the claim turns on. Thames Water, as a worked example, requires confirmation the leak has been fixed by way of a plumber's details and invoice, or a Thames Water job number if they carried out the repair themselves.
An invoice that will not be argued with says, on its face:
- The trading name, address and contact details of the company that did the work.
- The address where the work was carried out.
- The date the repair was completed, not just the invoice date.
- What was repaired and where, in plain terms. "Repaired split on 25mm MDPE supply pipe, approximately four metres from boundary stop tap, under front drive" beats "plumbing works".
- The amount charged.
Ask for that wording when you book, not after. A one-line invoice is the most common reason a pack has to go back for a rewrite.
2. Meter readings from before, during and after
Thames Water's form asks applicants to complete all parts including the meter readings. The calculation compares how much water you used in the past over a similar period against the amount the meter recorded while you had the leak, and where there is no usable history it falls back to typical use for a similar sized property.
That tells you exactly which readings are worth having:
- Before. Readings from bills covering periods before the leak started. These set the baseline the company will compare against. Dig out old bills rather than relying on the company's records.
- During. Your own dated readings while the leak was running, ideally including a pair taken hours apart with no water used, which establishes the rate of loss. How to take those readings properly matters here, because a reading taken while somebody is in the shower proves nothing.
- After. A reading on the day of the repair and another a few days later, which demonstrates consumption has returned to the baseline. This is the reading most people forget, and it is the one that proves the repair worked.
Photograph the meter face each time. A photograph carries a date and shows the digits you transcribed, which removes an entire category of dispute.
3. The dates
Write down when you first became aware of the leak, when any letter or email from the water company arrived, when you booked the repair, and when it was completed. Deadlines run from those dates. Thames Water's published conditions are that the leak is repaired within four weeks of them first notifying you or of the leak being identified, and that the allowance is claimed within three months of the repair date. Other suppliers set their own windows.
4. The detection report, if there was one
Where the leak was hidden and had to be traced, the detection report is not usually required for the allowance itself, but it is worth including. It documents that the loss was genuine, located and dealt with promptly, and it is the same document a loss adjuster will want if the water damaged the building. Our reports are written to be accepted for a trace and access claim; the insurance claims hub covers what that side expects.