Business electricity bills can be difficult to understand. As well as the cost of the electricity itself, there are other charges linked to the networks, infrastructure and wider energy system that support your supply.
One of these is DUoS charges, which stands for Distribution Use of System charges. These are electricity distribution charges that help pay for the local network that delivers power to homes and businesses.
For many businesses, DUoS charges are not always clearly explained on the bill. They may be included within your unit rates, standing charges or shown as a separate line item depending on your contract. This guide explains what DUoS charges are, how they are calculated, and whether businesses can reduce them.
DUoS charges are costs paid for using the local electricity distribution network. This is the part of the electricity system that moves power from the high-voltage transmission network to individual homes, businesses and sites.
National Grid Electricity Distribution explains that Distribution Use of System charges cover the cost of maintaining the distribution networks that supply electricity. In simple terms, DUoS charges help pay for the local cables, substations and equipment that allow electricity to reach your premises.
Businesses pay these charges because they use the distribution network every time they draw electricity from the grid. Even though the charge may be collected through your supplier, it is linked to the cost of operating the local network rather than the wholesale price of electricity.
DUoS charges help fund the maintenance, operation and development of the UK’s electricity distribution network. This includes the local infrastructure that carries electricity from the wider grid to your business site.
The distribution network includes equipment such as cables, poles, substations and transformers. Energy Networks Association explains that distribution network operators manage the local electricity networks that carry electricity to homes and businesses.
These networks need ongoing investment. As more businesses install EV chargers, heat pumps, solar panels, battery storage and other low-carbon technologies, the distribution network needs to adapt. DUoS charges are one way the cost of maintaining and upgrading this infrastructure is recovered.
DUoS electricity charges are not calculated in one simple way for every business. They can vary depending on your location, meter type, voltage level, agreed capacity, usage pattern and the time of day electricity is used.
For larger business customers, DUoS charges may include different elements such as fixed charges, capacity charges, excess capacity charges, reactive power charges and time-banded unit rates. National Grid Electricity Distribution guidance shows that some LV and HV business tariffs are grouped by capacity and include red, amber and green DUoS unit rates, alongside fixed and capacity-based charges.
This is why two businesses using the same amount of electricity may not pay the same DUoS costs. A business using more electricity during higher-cost peak periods may face higher distribution charges than one that can shift more usage into lower-cost periods.
Most businesses that use electricity from the distribution network will pay DUoS charges in some form. This includes offices, shops, care homes, manufacturers, warehouses, hospitality businesses and multi-site operators.
The charge is usually passed through by the energy supplier. In some contracts, it may be included within the overall unit rate or standing charge. In others, it may appear more clearly as a separate pass-through or network charge.
This can make DUoS charges easy to miss. A business may be paying them even if the invoice does not show the term “DUoS” clearly. That is why it is important to understand the full structure of your business electricity charges rather than only looking at the headline unit rate.
DUoS, TNUoS and CCL are different charges, but they can all appear as part of business energy bill charges.
DUoS covers the cost of using the local electricity distribution network. This is the lower-voltage network that delivers electricity from the wider grid to your premises. National Grid Electricity Distribution describes DUoS as covering the cost of maintaining the distribution networks supplying electricity.
TNUoS, or Transmission Network Use of System charges, relates to the high-voltage transmission network. NESO explains that TNUoS charges recover the cost of installing and maintaining the transmission system in England, Wales, Scotland and offshore.
CCL, or Climate Change Levy, is different again. It is a government environmental tax charged on taxable commodities such as electricity and gas used by businesses. GOV.UK explains that Climate Change Levy main rates are listed on a business’s energy bill.
A simple way to think about it is this: DUoS pays for the local distribution network, TNUoS pays for the national transmission system, and CCL is a tax applied to business energy use.
Businesses cannot avoid DUoS charges completely if they use the electricity distribution network. However, some businesses may be able to reduce their exposure through better energy management and procurement planning.
For half-hourly metered sites, using less electricity during expensive peak periods may help reduce time-banded DUoS costs. This could involve reviewing when high-load equipment runs, shifting some activity to lower-cost periods, using battery storage, improving efficiency or better managing EV charging.
Businesses should also review their agreed capacity. If a site is paying for more capacity than it needs, or regularly exceeding its agreed capacity, this may affect costs. National Grid Electricity Distribution guidance shows that some business tariffs include capacity and excess capacity charges, which makes capacity management important for larger users.
The right approach depends on the site. For some businesses, the savings may come from changing behaviour. For others, it may come from better contract structure, smarter metering, load management or a wider energy strategy.
DUoS charges have been affected by wider changes in the electricity system. As the UK moves towards more low-carbon technology, electricity networks need more investment and more flexible charging methods.
Ofgem launched a separate DUoS Significant Code Review in 2022 to look at how Distribution Use of System charges should work. In 2025, Ofgem said the reform of DUoS charges aims to make sure electricity networks are used efficiently and flexibly, while helping avoid unnecessary costs on energy bills.
For businesses, this means DUoS charges are not static. They can change as charging rules, network investment and electricity demand patterns change. Businesses should expect network charges UK-wide to remain an important part of commercial electricity costs, especially as demand from electrification continues to grow. For a full breakdown of what appears on your bill, see our guide on how to read your business energy bill.
One common misunderstanding is that suppliers set DUoS charges themselves. In reality, suppliers usually collect or pass through the charge, but the cost is linked to the local distribution network and the regulated charging framework.
Another misunderstanding is that businesses can avoid DUoS charges by switching supplier. Switching supplier may change how the charges are presented or priced within your contract, but it does not remove the underlying network cost if your business still uses the distribution network.
Some businesses also assume DUoS is only relevant for large industrial sites. While the impact is often more visible for half-hourly metered or high-usage businesses, many commercial electricity customers pay DUoS charges in some form through their bill.
At E for Energy, we help businesses understand what they are really paying for on their electricity bills. This includes reviewing DUoS charges, TNUoS charges, CCL, standing charges, pass-through costs and wider commercial electricity costs.
We can help identify whether your charges are being presented clearly, whether your contract structure is suitable, and whether your usage pattern is creating avoidable costs. For larger or half-hourly metered sites, we can also support with capacity reviews, load management and procurement strategy.
If your business wants clearer insight into network charges and a practical plan to manage energy costs, E for Energy can help review your bills and explain the options in plain English.