Distribution Use of System
Every electricity bill in Great Britain includes a charge you almost certainly haven't heard of: DUoS, the Distribution Use of System charge. It pays for the wires, transformers, and substations that make up your local distribution network — the infrastructure that runs between the high-voltage national grid and the socket on your wall.
DUoS is collected by the fourteen Distribution Network Operators (DNOs) that divide up Great Britain geographically. Each DNO sets its own rates, which is why someone in South West England pays a materially different network charge from someone in Yorkshire, even on otherwise identical tariffs.
The Red, Amber, and Green system
The unit-rate portion of DUoS isn't flat — it varies by time of day using a three-band system:
- Red — peak demand periods (typically 16:00–19:00 on weekdays). The most expensive band. Rates are 10–100× higher than Green in some regions.
- Amber — shoulder periods (mornings and early evenings). Mid-range.
- Green — nights, weekends, and most of the day. Cheapest or free.
This structure was designed to send a price signal: if you can shift consumption out of the peak window, the network needs less capacity investment and everyone pays less over time.
The standing charge
Alongside the unit rates, DUoS includes a fixed daily charge (p/MPAN/day) — one component of the standing charge you see on your bill. This covers the baseline cost of being connected to the network at all, regardless of how much electricity you use.
Rates by region
Each DNO defines its own Red/Amber/Green windows. The grid shows band structure across all 14 regions for
Annual cost calculator
Use the controls below to estimate the DUoS component of an electricity bill for a given region, year, and consumption level. The cost is split into what goes to each time band and to the standing charge.
Compare regions
How does DUoS cost vary across all 14 DNOs at the same consumption level? Costs are calculated using a fixed consumption split of 15% red / 45% amber / 40% green — a round-number approximation of the national D0018 PC1 average. Select a year and consumption to compare.
Rate trends
How have annual DUoS costs changed over time? At 2,700 kWh with 15% red / 45% amber / 40% green consumption split.
About this data
Rates are sourced from each DNO's annual charging statements (published each spring for the following April–March charging year). All figures are for the Domestic Aggregated tariff class — the tariff applied to standard domestic (household) meters.
Data gaps: HYDE (Scottish Hydro) is missing 2022/23 and 2025/26; NORW (Electricity North West) and SPOW (SP Distribution) are missing 2023/24 and 2024/25 due to non-standard PDF formats in those years.
Methodology note: The cost calculator uses the D0018 PC1 demand profile (actual settlement data from 2023/24) to estimate what fraction of a typical household's annual consumption falls in each time band. This fraction is fixed regardless of total consumption — the underlying demand shape doesn't change when you use more or less electricity.