27 March 2026

Transmission Network Use of System (TNUoS) charges

Transmission Network Use of System (TNUoS) charges are fees levied to recover the cost of building, maintaining and operating Great Britain’s electricity transmission network. TNUoS charges ensure that the costs of the transmission system are paid for by those who use it, with larger energy consumers paying the lion's share of the costs.


Who pays TNUoS charges?

TNUoS charges apply to both electricity generators and electricity users. For most businesses the charge is recovered through their electricity supplier, with TNUoS costs either forming part of the Standing Charge, or being a separate line item.


How do TNUoS charges work in practice?

The TNUoS charge is a per day amount -- similar to the normal standing charge -- set by the relevant Distribution Network Operator (DNO). The daily rate will vary depending on what TCR band the meter is in, with larger users normally classified as being in a higher TCR band and paying more. However, if you believe your meter has been incorrectly classified and is in the wrong TCR band, it can be reviewed by contacting the DNO.


How much is TNUoS (and when are charges set)?

TNUoS demand charges are set annually and published ahead of each charging year, which runs from 1 April to 31 March.

Unlike policy costs, TNUoS is not charged in p/kWh. Instead, it is levied as a p/day. This can add up to several tens of thousands of pounds per year for high usage meters.

With significant investment being made to upgrade the transmission network to accommodate renewable generation, it is likely that TNUoS costs will continue to rise in the coming years, perpetually accounting for a larger proportion of electricity bills.


Why TNUoS matters for businesses

For high-consumption and flexible sites, TNUoS represents a growing expenditure that is difficult to manage. Some businesses can get relief from the rising TNUoS costs from the Network Charging Compensation mechanism, introduced last year. However, for many businesses, the best they can do is to review that they are in the correct TCR band and are being invoiced correctly by their supplier.


If you would like to ensure that you are in the correct TCR band and that your TNUoS charges are being invoiced correctly. Contact us today and we can review your recent invoices to make sure you aren't paying more than necessary.

by Craig Watson 27 March 2026
With consumer spending declining and OFGEM raising their price cap, you would be forgiven for seeing February as a month where negative news was at the forefront, but in the energy markets, this was not the case.
by Craig Watson 27 March 2026
In a year that began with falling energy prices, there were recurring catalysts that led to prices climbing steadily higher. Geopolitical uncertainty and the perennial threat of escalating conflicts meant fear would maintain a constant presence in the wholesale markets. We will look back at the key energy stories from 2024, and how the energy markets are likely to shape up in 2025. Quarter 1  The year began with cautious optimism as the UK’s gas reserve levels were healthy and prices for the Summer’24 season were in freefall. In February, prices pulled back to their lowest levels since 2021, and for the first time in a while, we identified that there was greater potential for upside risk than for further downward price movement: “ there now (exists) an asymmetrical element of risk should the market encounter a supply-side problem of significance. ” During February we had advised customers on flexible contracts that this was an ideal time for making purchases. March would see prices begin to ascend again as international conflict would create problems with LNG imports, and we would highlight the geopolitical risks as an area for concern moving forwards: “ fears remain and there are potential negative catalysts that could lead to prices rising further, with the main factors to watch out for being based on geopolitical unrest. “ For a business that purchases their energy in advance, this quarter was the optimal time for purchasing during 2024. In February, electricity prices for Winter’25 were down to 7.75p/Kwh, and as low as 6.05p/Kwh for Summer’25. Winter’25 ended the year with prices above 11.1p/Kwh, with Summer’25 prices exceeding 9p/Kwh. For a company that uses 500,000Kwh of electricity per month, the difference between buying at the February low point compared to today’s prices would represent a yearly saving of over £200,000.
Show More