Understanding how water charges are calculated on a residential park can sometimes feel like wading through muddy waters. However, strict rules are in place across the UK to ensure you are billed fairly.
Whether your park home has its own meter or shares a communal supply, site owners must adhere to the regulations set by Ofwat. Here is a comprehensive breakdown of how water billing works for park homes, the maximum limits on what you can be charged, and what you should expect to pay based on the latest average bills.
The Maximum Resale Price: What is the Limit?
When a park owner buys water and sewerage services from the local water company and then resells them to residents, they are legally bound by the Maximum Resale Price.
- The maximum resale price is the most that anyone can charge another person for supplying water or sewerage services that they have bought from a water or sewerage company.
- Anybody reselling water or sewerage services should charge no more than the amount they are charged by the water company.
- They are also allowed to make a reasonable administration charge.
- The administration charge applies to each purchaser, not to each occupant.
Metered vs. Unmetered: How Charges are Calculated
The way your bill is worked out depends entirely on whether your individual park home has its own water meter.
If Your Park Home is Metered:
- Your reseller must charge you the same amount for each cubic metre as they pay the water company.
- They must also share the cost of the standing charge they pay the company equally between all purchasers.
- Resellers can charge purchasers with a meter an administration charge of about £10 a year.
If Your Park Home is Unmetered:
If there are no individual meters, the site owner cannot simply guess your usage. The water reseller must charge for water in one of the following six ways:
- Splitting the total charge equally between the purchasers.
- Charging in proportion to the number of people in each park home.
- Charging in proportion to the rateable value of the property.
- Charging in proportion to the floor space of the property.
- Charging in proportion to the number of bedrooms for each home.
- Splitting half the bill equally between purchasers, and the other half according to any one of methods 2-5.
For unmetered homes, resellers can charge purchasers an administration charge of about £5 a year.
Note: If a park has a mix of metered and unmetered homes, the reseller must work out the charges for metered purchasers first and subtract these from the total bill. They must then work out the charges for the unmetered purchasers using one of the six rules above.
Average Water Bills and Regional Variations
If your reseller charges you more than the average bill in your region, they must show that they worked out your bill using one of the permitted methods.
To give you an idea of what is typical, the national average water bill for the 2026/27 year is forecast to be £639. However, water scarcity, infrastructure, and local geography mean prices fluctuate significantly depending on where your park is located.
Here is a look at the latest forecast average annual bills across several key regions for 2026/27:
| Water Provider | Forecast Annual Bill (2026/27) |
|---|---|
| Northumbrian Water | £535 |
| Severn Trent Water | £587 |
| Yorkshire Water | £636 |
| Thames Water | £658 |
| United Utilities | £660 |
| Anglian Water | £674 |
| Dwr Cymru (Welsh Water) | £683 |
| Wessex Water | £695 |
| South West Water | £740 |
| Southern Water | £759 |
What To Do If You Are Overcharged
If you believe you are being overcharged, your first step should be to ask your reseller how they have worked it out. The reseller must provide you with all of the information they have used to work out your bill, and they must provide this in writing without charging you for it.