The National Energy System Operator (NESO) has published its latest Five-Year View of TNUoS (Transmission Network Use of System) tariffs. The headline is clear: a typical consumer could face an average increase of about 38% in total TNUoS costs in 2026/27. The main driver is higher demand residual revenues. Your actual impact will depend on location, connection, and consumption, so now is the time to budget and optimise.
Average rise: about 38% in total TNUoS for a typical user in 2026/27
Drivers: higher revenue recovery for transmission owners, increased grid investment, and slower progress on long term market reforms. Demand residuals carry much of the uplift
Locational effects: your TNUoS zone and usage shape exposure
Regional guide (illustrative): South West about 40%, London about 35%
Outlook: volatility likely until REMA outcomes take effect, currently targeted around 2029
| Demand TNUoS Charges | 2025/26 (Final) | 2026/27 (Forecast) | Change |
|---|---|---|---|
| HH Demand Tariff | £3.00/kW (avg) | £3.18/kW | ↑ £0.18/kW |
| NHH Demand Tariff | 0.38 p/kWh | 0.43 p/kWh | ↑ 0.05 p/kWh |
| EET (Embedded Export Tariff) | £3.00/kW (avg) | £3.45/kW | ↑ £0.45/kW |
| Demand Residual Revenue | £3.84bn | £7.52bn | ↑ £3.68bn |
Purpose: TNUoS pays for building, operating, and maintaining Great Britain’s high voltage transmission network
Who sets them: Ofgem sets the framework that allows transmission owners to recover allowable revenues through TNUoS, which suppliers and generators pay before costs flow to end users
Principle: user pays. Charges reflect the cost of transporting electricity across the national grid, with locational signals to encourage efficient use
Transmission owners must recover higher allowed revenues to operate and reinforce the system. Some historic offsets, such as prior year tax allowances, are reducing, which increases the net amount to collect.
More renewable generation is connecting far from demand centres. Moving clean power to where it is used requires new lines, substations, and system capability, which adds cost.
The Review of Electricity Market Arrangements (REMA) is still in progress. Until changes are implemented, likely close to 2029, the current framework must manage significant cost shifts.
For 2026/27, demand residual revenues account for a large share of the uplift, so many end users will feel the effect.
The material change is expected in the 2026/27 charging year, with further evolution through the decade as investment and policy develop.
TNUoS is locational, so percentage changes vary by zone:
| Region (illustrative) | Indicative change in total TNUoS for 2026/27 |
|---|---|
| South West | ~40% |
| London | ~35% |
| Others | Between these bounds |
Your exact outcome depends on zone, connection voltage, metering class (HH or NHH), agreed capacity, and coincidence with system peaks.
For C&I sites, TNUoS is a meaningful operating expense. Multi site portfolios that span zones can see very different outcomes, which creates both risk and optimisation opportunities.
Now to Q1 2026: build site level exposure models, set budgets, identify quick wins
2026/27: expect the step change, monitor monthly, adjust operations
2027 to 2030: continued grid build out, refresh forecasts annually
Around 2029: REMA outcomes begin to reshape incentives and charging signals
We support C&I customers that want to quantify exposure, control it, and reduce it.
TNUoS diagnostics that include zonal mapping, HH data analysis, and site level bill impact modelling
Capacity and profile optimisation from paperwork through to plant changes
Business cases for on site assets such as solar, storage, and controls, with measured benefits