Some households are paying hundreds of pounds more than they need to for water supply - is yours one of them?
No, unlike with other utilities, it's not possible to choose who supplies water to your home, as every property in the country falls within one of 26 water areas, each of which is 'owned' by a single water company.
This means there's no price-reducing competition between suppliers and you can't shop around for a better deal.
However, there is an alternative that could help you to cut your water bill significantly: switching to a water meter.
It's not a given that switching to a water meter will help you to pay less, but it's well worth investigating.
Most homes in the UK - at least those built pre-1990 - are on an unmetered supply. This is where the amount you pay for your water is determined by the rateable value of your property.
Rateable values in no way reflect the number of people living in your property or the amount of water you use. Instead, they were set by local authorities in 1990 and have not been up for debate or revision since.
It's because of this that a metered water supply could work out so much cheaper for some people as you only pay for the water you actually use - the difference could be hundreds of pounds.
A general rule of thumb is that if there are more bedrooms than occupants in your property then switching to a water meter is likely to be worth your while.
If your house is relatively 'full' then staying on an unmetered supply may be best as you will still pay the same amount for your water however much you use.
The Consumer Council for Water have a water calculator on their website that you can use to work out whether getting a water meter installed is worth your while.
Alternatively, you can contact your water supplier to request a more accurate estimate of the potential saving. A list of water companies' contact details is available on the Ofwat website.
Generally, if the saving is significant then getting a meter installed will be worth your while. If there isn't much in it you may be better off staying as you are just in case.
Once you switch to a meter it will be in your interest to be as economical with water as possible as you'll be paying for every drop you use.
If the water company can't install a meter then they'll change you to an assessed tariff and you'll be billed based on an estimated usage.
While this isn't quite as ideal as having a meter fitted, it will mean you still benefit from reduced rates if a water meter would have helped you to save.
If you live in England or Wales it's almost always free to get a water meter installed.
Your water company will aim to get one fitted within 3 months of you requesting it. If they are unable to do this they will usually estimate how much you will pay on a water meter and adjust your bill accordingly until you get one installed.
If you live in Scotland, getting a water meter installed is going to cost you. As this can often be a significant amount, getting one installed is unlikely to be worth your while unless you live in a particularly large property.
If you're unsure as to whether you're on a metered or unmetered water supply you simply need to contact your water company and ask. Contact details of all water companies are available on the Ofwat website.
All properties built after 1990 have had water meters installed so if your home is relatively new it's likely that you're on a metered supply.
Once you have a water meter fitted you'll have 12 months within which you can switch back to an unmetered supply if it's more expensive.
For this reason it makes sense to periodically take water meter readings and feed them back to your water company so that they are able to provide you with an accurate bill.
If you move in to a property with a water meter already fitted, or your water company ask that you install a water meter it won't be possible to switch back to an unmetered bill.
If you're in rented accommodation and have a fixed tenancy of at least 6 months, you can ask for a water meter to be fitted to your home. It is a good idea to get your landlord's permission first.
It's possible that installing a water meter could impact your home's value slightly. However, it's unlikely to be significant, as many water companies install meters to properties when new occupants move in anyway.
When you switch to a metered supply you pay only for the water you use. While this gives you the potential for big savings, it also means that you'll foot the bill for any leaks so vigilance is needed.
If you receive an unexpectedly large water bill but haven't significantly changed your usage you should check for leaks.
To do this turn off your internal water supply and check your water meter, if the dials are still spinning it's likely that there is a leak somewhere.
Once you notice a leak you should notify your water company as soon as possible and they'll be able to advise you as to what to do next.
Where the leak is will determine both who fixes it and who pays for it.
If the leak is inside your home it'll be down to you to get a plumber in to do the repairs.
If the leak is outside your property but inside your property boundary you'll need to pay for repairs if excavation is needed. However, your water company may offer to do the repairs if it's easily accessible.
Providing you get the leak fixed within a reasonable amount of time (usually 30 days) the water company may agree to reduce your bills to their usual level. They may also give you some help towards the cost of repairs, but this is not a given.
Some home insurance policies will pay out to cover the cost of water leakages so it's worth checking to see whether you'd be covered and perhaps looking at adding this in if not.
If you're on a metered supply and are struggling to pay your bill you should contact your water company as soon as possible to discuss your options. You may be eligible for assistance from their Water Sure scheme.
This is available to individuals that:
have a medical condition that means they need to use lots of water
are in receipt of certain benefits and have at least 3 children