I questioned a massive hike in water bill and now they’re looking for leaks

[NaughtbutKeys]

Seems fair but I’m now scared stiff.

What is the worst case scenario if there is an underground leak that’s our issue?

It could also be a tap or the loo, even a small one can add a lot to your bill if it's dripping all day and night. Check everything inside first just in case, unless it's anything obvious such as a change in occupants or usage.

Surely if your meter readings have shot up that would mean the leak would have to be after the water had passed through your meter though - hence inside your house? If there was a leak in the pipes outside your house then that water wouldn't be reaching your meter and so not measured? If you had a big leak indoors I think you'd know about it, though it's true that something like a faulty toilet could be using quite a lot of water.
I got a ridiculous water bill once - something stupid like £11000 for a quarter for just me and DH. They asked about leaks then, but I'd have been living under water permanently if there was a leak that big in my house! It turns out they'd read the meter wrong. It was a new build so the meter was reading something like 000123 but I got charged for 123000. Are you certain they've got the right figures or that there isn't a fault with the meter?

We turned off the stop cock and ran all the taps dry. The water meter was still running.

the water meters are still relatively new (less than 20 months I think) . They are in next-doors garden and were put into a previously lawned area of an elderly man and then heavily concreted over. We had no say in it.

Does anyone know how I can check anything myself? I’m worrying myself silly - there’s no cash in the pot for major repairs

Ask the water company to prove that supply isn't feeding anywhere else apart from your property.

If the leak is between the meter and the house then once it is repaired ring the billing department of your water company and ask about a Leakage Allowance.

Hi OP,
Does your home insurance include trace and access and loss of metered water? If so you can claim off them. Many water companies also offer a leakage allowance as a PP said.

If you turned off the stop cock and nothing in your house was using water at the time then it's either a dodgy meter or it's been wrongly installed on a connection that's serving more than one property and you're paying for your neighbours usage too! The fact it's installed the neighbours garden would ring alarm bells for the later option to me.