For a home in London, Thames Water is the main regional benchmark. Its forecast 2026/27 household average is £658 a year.
Some outer London addresses may be supplied by Affinity Water or SES Water. Water-company boundaries can cross postcode areas and clean water may come from a different company than wastewater.
Monthly and weekly equivalent
The annual company average works out to £54.83 a month or £12.65 a week. Your payment plan may collect over ten rather than twelve months, so instalments can differ.
Household-size examples
These planning estimates adjust the Thames Water company benchmark for typical occupancy. They are not tariff quotes.
| Household | Annual estimate | Monthly |
|---|---|---|
| 1 person | £412 | £34.33 |
| 2 people | £593 | £49.42 |
| 4 people | £892 | £74.33 |
Coverage around London
Thames Water is associated with postcode areas including E, EC, EN, HA, HP, LU, N, NW, OX, RG, SE, SL, SW, TW, UB, W, WC. This is only a regional guide: postcode areas can contain more than one appointed company, and wastewater may be billed separately.
What changes a London bill?
- A metered home pays for measured use plus fixed charges.
- An unmetered home normally pays according to historic rateable value.
- Occupancy and habits strongly affect metered consumption.
- Support tariffs and WaterSure can reduce eligible bills.
Use a localised estimate
Select Thames Water in the calculator, add your household size and choose a realistic usage level. Treat the output as a planning range, then compare it with the tariff details on your bill.