Updated on 21 May 2015.
You can't switch water supplier like you can gas and electric. So it's simply a case of finding out which water company supplies the area in which you live.
Then you can get an account set up and arrange how you'll pay your bill - that way you won't risk having your water supply cut off!
If you've just moved in, you should be able to find out either from the previous owners, tenants or landlord.
If you don't have the contact details of your home's previous occupier, you can still find your supplier relatively easily.
If you live in Scotland, your water will be supplied by a public company, Scottish Water.
In Northern Ireland, water and sewerage services are provided by Northern Ireland Water, a company owned by the government.
If you live in England or Wales, your water will be supplied by one of 32 private companies. You can check the Consumer Council for Water's website or the Ofwat website to find out which water company supplies your area.
If you live on the border of two water areas, then you should contact the possible water companies directly for confirmation. A full list of contact details is available on the Ofwat website.
Some companies supply the water to your home and collect the wastewater from your sinks and toilets.
Others only supply you with water - in these cases you'll need to find the company that collect your waste water too.
If your new property has a water meter, it's worth taking a reading and passing it on to the supplier as soon as you can. That way you can make sure your bills are accurate and you won't end up paying for water used by the previous occupiers.
If you just want to cut your water bills, read our guide: 5 Easy Ways to Save Money on Your Water Bill.
Written by Dan at money.co.uk
Could getting a water meter save you money? And do water companies do enough to help you decide? Our survey has found millions regret getting one - but nearly half have saved money. Here's how to decide...
Are you paying too much for your water? There are loads of great ways you can save money on your bills and save water at the same time.
Some households are paying hundreds of pounds more than they need to for water supply - is yours one of them?
The regulator Ofwat has set a UK-wide plan to cut water bills by 5% over the next 5 years. We look at how their plans will affect you and if you really stand to save as much on your water bill as it suggests.
3.6 million Regret Their Water Meter... But Will It Save You Money?
5 easy ways to save money on your water bill
The simple way to save £100s on your water bill
Ofwat Unveil 5% Water Bill Cut... But Does It Go Far Enough?
Paying Too Much For Water?
Ofwat Fights to Cut Your Water Bill By 5%
Could a water meter save you up to £100 a year?
Get expert tips that will help you spend and save smarter, even if you're short on time.