What evidence do I need?

Generally proof that there was a leak, proof it has been repaired, and something establishing when. Meter readings with dates and times cover the first and third, and a plumber's invoice or receipt covers the second. Photographs of the meter at both readings are worth more than a written note, because they timestamp themselves.

It depends on the company and it is the thing to check first. A window measured from when the leak was discovered is common, which means the clock may already be running while you are deciding what to do.

Do I need a professional to repair it?

Sometimes, and it is worth knowing before you fix it yourself. Some policies require evidence of a repair in a form a DIY fix cannot easily provide, so the cheaper repair can cost more than it saves.

Ask for the reason against the published policy, because a refusal against a written term is checkable. If it is a discretionary refusal rather than a term you failed, the consumer body for water customers exists for exactly that kind of dispute and its involvement is free.

Should I still claim if the leak was small?

Work out the volume first rather than guessing. A small rate over a long period is a large volume, and how long the leak ran matters as much as how fast it was. The calculators here give the annual volume, which is what a claim is actually about.

How to apply for a leak allowance

Read your company's policy before arranging the repair rather than after it. A repair deadline and a requirement to claim rather than be credited automatically are two of the axes these policies differ on, and if yours has either, it is impossible to satisfy retrospectively. Everything else about a claim is recoverable. Those two are not.

Last reviewed 14 August 2026

The short answer

Six steps, and the first one has to come before the repair rather than after it.

Read your own company's leak allowance policy. Look specifically for a repair deadline and for whether a claim is required or an allowance is automatic.
Establish which pipe leaked, by closing the internal stop tap and repeating the meter test. Supply pipe leaks are the usual case an allowance covers.
Record the evidence: meter readings with dates and times, photographed rather than written down.
Arrange the repair, within whatever window the policy states, and in whatever form the policy requires evidence of.
Take a second pair of meter readings afterwards. A before-and-after pair demonstrates the repair worked, which is more persuasive than an invoice alone.
Submit the claim, and ask about the sewerage element and about a subsidised repair at the same time, because they are separate policies.

Only the first step is genuinely time-critical, and it is the one people do last. Discovering a repair window after the repair is the single most common way an otherwise valid claim is lost.

How this works in practice

The evidence a claim rests on is mostly things you already generate by measuring the leak properly, which is why the measurement and the claim are worth thinking about together.

Evidence	What it proves
Two meter readings with dates and times, photographed	That there was a loss, how fast, and when it was measured.
A repair invoice or receipt	That it was fixed, by whom, and when.
Two more meter readings after the repair	That the loss has stopped. This is the one people skip and it is the most persuasive of the three.
The bill showing the affected period	What was actually charged for the volume in question.

What each piece of evidence establishes

All of the meter evidence comes free with doing the test properly in the first place. measure the rate of loss at the meter produces readings, times and a rate, and photographing the register rather than writing it down costs nothing and timestamps itself.

What changes the answer

Four things, and two of them are decided before you make the claim at all.

Whether you read the policy before repairing. A missed window cannot be recovered afterwards.
Who did the repair, if the policy requires evidence in a particular form. A DIY fix can be cheaper and still cost the allowance.
Whether this is a first leak, and whether your company's policy grants a repeat.
How long the leak ran. The credit usually covers a stated period rather than the whole history, so a leak found early is worth more than the same leak found late.

That last point is the one worth acting on today. Every week a leak runs undetected is volume that may fall outside whatever window the allowance covers, whatever the rate.

Assumptions and sources

Litres in a cubic metre

Exact by definition

SI definition. The litre is defined as one cubic decimetre, so one cubic metre is exactly 1,000 litres.

Days used for an annual figure

Editorial convention

Annual figures on this site are a daily rate multiplied by 365. Leap years are not modelled, so a leap year is understated by one day, which is 0.27 per cent.

Where the first severity band ends

Editorial convention

A practical threshold set just above the 0.4 litres per hour starting flow quoted for a DN15 meter with the TVM register. It is not a meter accuracy tolerance. Against the STANDARD it sits about 31 times below Q1, the 15.6 litres per hour at which OIML R 49-1 first defines any permitted error. Against THIS MANUFACTURER it sits about 6 times below 3 litres per hour, the lowest flow at which Itron volunteers a typical accuracy that the standard does not require. Neither figure reaches down to 0.5, so nothing quantifies a reading here on either footing. Meters with other registers start higher, so this threshold sits above the most sensitive case rather than above every meter.

The steps here are the shape a claim generally takes rather than any one company's process, and every company publishes its own. This page describes what to have ready and in what order, because that part is common; what a specific policy requires is on that company's own page.

No amount is quoted anywhere, because no supplier rate on this site has been verified and any figure would be invented. What a claim needs is the durable part.

What to do next

Two things, and the first one today rather than after the repair.

Find and read your own company's policy, looking first for a repair window and for whether a claim is required. That is five minutes and it is the only irreversible part.
Photograph your meter now, with the time. Whatever happens next, a dated reading from before the repair is evidence you cannot generate later.

And know what you are claiming for before you ask. what an allowance actually credits covers the water element, the sewerage element and the repair separately, because they are three different questions.

Common questions

What evidence do I need?: Generally proof that there was a leak, proof it has been repaired, and something establishing when. Meter readings with dates and times cover the first and third, and a plumber's invoice or receipt covers the second. Photographs of the meter at both readings are worth more than a written note, because they timestamp themselves.
How long do I have?: It depends on the company and it is the thing to check first. A window measured from when the leak was discovered is common, which means the clock may already be running while you are deciding what to do.
Do I need a professional to repair it?: Sometimes, and it is worth knowing before you fix it yourself. Some policies require evidence of a repair in a form a DIY fix cannot easily provide, so the cheaper repair can cost more than it saves.
What if they say no?: Ask for the reason against the published policy, because a refusal against a written term is checkable. If it is a discretionary refusal rather than a term you failed, the consumer body for water customers exists for exactly that kind of dispute and its involvement is free.
Should I still claim if the leak was small?: Work out the volume first rather than guessing. A small rate over a long period is a large volume, and how long the leak ran matters as much as how fast it was. The calculators here give the annual volume, which is what a claim is actually about.