Where exactly does my responsibility start?

At the boundary of the property, which is usually where the external stop tap sits, often in a small chamber in the pavement or just inside the gate. From there to the house the pipe is generally the property owner's. Before it, the company's.

The leak is under my drive. Whose is it?

Almost certainly yours, because a drive is inside the boundary. That surprises people, because the pipe is buried, nobody chose where it went and it may have been laid decades ago, but the ownership follows the boundary rather than how accessible the pipe is.

Does the water company have to fix it?

Not on your side of the boundary. Many companies do offer a free or subsidised first repair on the supply pipe as a matter of policy rather than obligation, which is separate from the leak allowance and is worth asking about at the same time.

What if I share a supply pipe with neighbours?

Then it is shared responsibility, and it complicates everything: the repair, the allowance, and the meter test, because a shared pipe cannot be isolated to one property. Shared supplies are common in older terraces and in converted properties.

Is this the same everywhere in the UK?

The general arrangement is, but the detail is set by different legislation in England and Wales, Scotland and Northern Ireland, and this page has not read the instrument for each. Treat the boundary rule as the shape of the answer and your own company as the authority on your case.

Who is responsible for the supply pipe

The dividing line is the property boundary, not the wall of the house. The water company is generally responsible for the main and the communication pipe up to the boundary, and the property owner for the supply pipe from the boundary to the property. So a leak in your own front garden is very likely yours, even though it is nowhere near the building.

Last reviewed 14 August 2026

The short answer

Three lengths of pipe bring water to a house, and they do not all belong to the same person.

The pipe	From	Generally the responsibility of
The main	Under the street	The water company.
The communication pipe	The main to the boundary, usually to the external stop tap	The water company.
The supply pipe	The boundary to the property, including under your garden and drive	The property owner.
Internal plumbing	Inside the building	The property owner.

Who owns which length

The third row is the one that catches people. It is buried, you did not lay it, you cannot see it, and it is still generally yours. That combination is also the reasoning these allowances rest on, since a leak you could not have noticed is a different proposition from one you could.

How this works in practice

The meter test locates the leak relative to that boundary without anybody digging, which is why it is worth doing before any conversation about who pays.

Close the internal stop tap, usually under the kitchen sink or where the supply enters the building, and repeat the meter test.
If the meter stops, the loss is inside the property and downstream of the stop tap. Internal plumbing, and internal allowances are less common.
If the meter keeps moving, the loss is between the meter and the stop tap, which is the supply pipe. Generally yours, and the case an allowance is most likely to cover.

That single test decides which of two quite different problems you have, and it costs an evening. the threshold a moving meter has to clear covers what to close and what commonly gets missed.

The legislation behind the general arrangement in England and Wales is the Water Industry Act 1991, and each company sets out its own position in its charges scheme and its leak policy. Scotland and Northern Ireland are governed separately.

What changes the answer

Four things, and the first two are common enough to check before assuming anything.

A shared supply pipe, common in older terraces and converted properties. Responsibility is shared, the meter test cannot isolate one property, and both the repair and any allowance become a conversation between several households.
Where the meter actually is. A meter in a boundary chamber measures the supply pipe; one fitted indoors after the stop tap does not, so an underground loss is invisible to it.
Company policy on top of the legal position. Many offer a free or subsidised first supply pipe repair as a matter of policy, which is separate from an allowance and separate from who is legally responsible.
Which nation you are in. The general boundary arrangement holds, but the governing legislation differs between England and Wales, Scotland and Northern Ireland.

None of those changes the volume. They change who pays for the water and who pays for the repair, which are two separate questions with two separate answers.

Assumptions and sources

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 boundary arrangement described here is the general shape rather than a reading of an instrument for each nation. The detailed position is set separately in England and Wales, in Scotland and in Northern Ireland, and this page has not read all three for this question, so it says what is general and points at your own company for what applies to you.

What is not in doubt is the practical test: closing the internal stop tap and repeating the meter reading locates the loss relative to the boundary, and that works identically everywhere because it is plumbing rather than law.

What to do next

Three things, and the first is what makes the other two possible.

Run the stop tap test before contacting anybody. Knowing whether the loss is inside or on the supply pipe changes the whole conversation, and it takes one evening.
Ask your company about a free or subsidised first repair as well as about an allowance. They are separate things and being told about one is not being told about the other.
If the supply is shared, establish that early. It changes who is responsible, what can be tested, and who has to agree to a repair.

And keep the readings either way, because they are the evidence for both conversations. whether a leak allowance can reduce that charge covers what an allowance actually credits.

Common questions

Where exactly does my responsibility start?: At the boundary of the property, which is usually where the external stop tap sits, often in a small chamber in the pavement or just inside the gate. From there to the house the pipe is generally the property owner's. Before it, the company's.
The leak is under my drive. Whose is it?: Almost certainly yours, because a drive is inside the boundary. That surprises people, because the pipe is buried, nobody chose where it went and it may have been laid decades ago, but the ownership follows the boundary rather than how accessible the pipe is.
Does the water company have to fix it?: Not on your side of the boundary. Many companies do offer a free or subsidised first repair on the supply pipe as a matter of policy rather than obligation, which is separate from the leak allowance and is worth asking about at the same time.
What if I share a supply pipe with neighbours?: Then it is shared responsibility, and it complicates everything: the repair, the allowance, and the meter test, because a shared pipe cannot be isolated to one property. Shared supplies are common in older terraces and in converted properties.
Is this the same everywhere in the UK?: The general arrangement is, but the detail is set by different legislation in England and Wales, Scotland and Northern Ireland, and this page has not read the instrument for each. Treat the boundary rule as the shape of the answer and your own company as the authority on your case.