BILLDECODER GUIDE
TUOS (Transmission Use of System) and DUOS (Distribution Use of System) are network charges that pay for moving electricity from power stations to your business. Think of transmission as the highways — high-voltage lines that carry electricity long distances from power stations to regional substations. Distribution is the local streets — the poles, wires, and transformers that deliver electricity from the substation to your front door.
Together, TUOS and DUOS typically make up 40–50% of your total electricity cost. You can't negotiate them directly — they're regulated by the Australian Energy Regulator (AER) and passed through by your retailer at the regulated rate. However, the tariff structure they're calculated on can sometimes be reviewed, and reducing your demand can lower the demand-based component of network charges.
Network charges (TUOS + DUOS) typically make up 40–50% of your total electricity cost — the single largest component of most bills.
TUOS charges pay for the high-voltage transmission network — the big power lines on tall steel towers that you see running across the countryside. This network carries electricity from power stations (coal, gas, wind, solar farms) to regional substations at very high voltages (66kV to 500kV).
Transmission networks in Australia are owned and operated by companies like TransGrid (NSW), AusNet Services (Victoria), Powerlink (Queensland), and ElectraNet (South Australia). The rates they charge are regulated by the AER through a revenue determination process that happens every five years.
TUOS is typically the smaller of the two network charges, making up roughly 8–12% of your total electricity cost. Your retailer passes TUOS through as a line item or bundles it into the network charges on your bill.
DUOS charges pay for the local distribution network — the poles, wires, substations, and transformers that deliver electricity from the regional substation to your business premises. This is the infrastructure you see in your street — the wooden poles, the green transformers on concrete pads, and the wires running to your building.
Distribution networks are owned by companies like Ausgrid, Endeavour Energy, and Essential Energy (NSW), CitiPower and Powercor (Victoria), Energex and Ergon Energy (Queensland), and SA Power Networks (South Australia).
DUOS is the larger of the two network charges, typically making up 30–40% of your total electricity cost. It includes both fixed daily charges and variable charges based on your usage and demand.
Australia has one of the longest and most distributed electricity networks in the world — over 900,000 kilometres of power lines serving a relatively small population spread across a vast area. That infrastructure is expensive to build, maintain, and upgrade.
Network costs increased significantly in the 2010s due to major infrastructure investment programs. While the rate of increase has slowed, the existing infrastructure still needs to be paid for. Network charges are regulated by the AER to ensure they're reasonable, but they remain the largest single component of most electricity bills.
For businesses in rural or regional areas, network charges tend to be higher because the same infrastructure serves fewer customers. Urban businesses generally benefit from lower per-customer network costs due to higher population density.
You can't negotiate the network rate — it's regulated and the same for all customers in your network area. But there are several things you can do:
Check your network tariff assignment. Businesses are assigned a network tariff by their distributor. Sometimes you're on a tariff that doesn't match your usage pattern — for example, a demand-based network tariff when a time-of-use tariff would be cheaper. Your retailer or an energy consultant can request a tariff review.
Reduce your demand. Network charges often include a demand component (especially for businesses). Reducing your peak demand — by staggering equipment startup, for example — can lower both your retailer's demand charge and the network demand charge. See our demand charges guide.
Shift usage to off-peak. If your network tariff has time-of-use pricing, shifting electricity use to off-peak periods reduces the variable component of network charges.
Solar and battery storage. Generating your own electricity reduces the amount you draw from the grid, which lowers the usage-based component of network charges. Battery storage can also help manage demand peaks.
Can I switch network providers to get cheaper TUOS/DUOS?
No. Your network provider is determined by your physical location — you can't choose a different one. But you can review whether you're on the optimal network tariff for your usage pattern, which can affect how network charges are calculated.
Are TUOS and DUOS the same in every state?
No. Each state has different network providers with different regulated rates. Network charges in rural areas tend to be higher than in cities because the infrastructure serves fewer customers over greater distances.
Do solar panels reduce my network charges?
They can reduce the usage-based component of network charges by reducing the amount of electricity you draw from the grid. But the fixed daily network charge and any demand-based network charges may not be affected.
Want to see network charges on your own bill?
Upload your bill and we'll break down every charge — including TUOS, DUOS, and how they compare to other businesses in your area.
Analyse your business billLast updated: March 2026