lovingit If I understand you correctly, you went from £26 unmetered to £47 metered.
MoneySavingExpert have a chart of average charges per water company and price rises for 2025/26.
www.moneysavingexpert.com/news/2024/12/water-bills-rise-england-wales-2025/
The average bill for United Utilities was £486 and will now be £598, a rise of 23% or £112 per year. That 23% ties in with your rise from £47 to £55 but that suggests above average use.
United Utilities provide comprehensive annual guides to explain how their charges work:
Current year:
www.unitedutilities.com/globalassets/documents/pdf/household-charges-scheme-2025-2026.pdf
Last year:
www.unitedutilities.com/globalassets/documents/pdf/household-charges-scheme-2024-25.pdf
If you don’t qualify for any of the special schemes e.g. low income or medical needs, jump to sections four and five.
Your bills should have a breakdown that you can tie to those numbers. Your pre-metered bills will show your rateable value.
What you need to take into account is the basic difference between the two systems.
Under a metered system, the variable is the amount of water used. The more water used, the higher the bill.
Under an unmetered system, the variable is the rateable value of the propery. The higher the rateable value, the higher the bill.
Therefore, under an unmetered system, someone living in a property with a higher rateable value is going to pay more than someone in a property with a lower rateable value even though their water usage may be the same. This is why it’s usually advantageous for people living in larger properties with high rateable values to be metred and may not be advantageous for those in smaller properies with lower rateable values. I wonder if that is the case here.
Domestic rateable value is based on an assessment of a property's estimated annual rental value. The last comprehensive assessment of domestic properties for rateable values happened in 1973, with some amendments and additions up to 1990. In other words, your rateable value may take no account of rent rises over the last 35 years or longer. Water companies do take this into with higher fixed charges for unmetered water and may make other adjustments - see 5.1.1.
United Utilties covers the north west of England. If you have eliminated the possibility of a meter malfunction or a leak, I’d hazard a guess that the reason your bill is higher now could be that you were getting a good deal under the unmetered system due to your house having a low rateable value.
All that said, £55 a month does sound high. I’m a single occupant and use water carefully using about 40 cubic litres a year. I’m in a region where the average bill is slightly higher than United Utilities. My estimated bill for this calendar year is £400 (two thirds of average use) so I currently pay £33 a month metered.
A cubic litre is a 1000 litres or 220 gallons. A 1000 litres is about 12 baths or 28 showers or 14 machine washes.