The UK Emissions Trading Scheme (UK ETS) has been in operation since January 2021. For many large industrial and energy businesses, it is a significant compliance obligation. For the rest of UK businesses, it is a cost driver, one that feeds into electricity prices whether or not you are directly regulated by the scheme.

Either way, it pays to understand how it works. Carbon pricing is now a structural feature of UK energy markets, not a temporary policy experiment, and its effects will only grow as the cap tightens over the coming years.

What the UK ETS Actually Is

The UK ETS replaced Britain’s participation in the EU Emissions Trading System after Brexit. The core mechanism is cap-and-trade.

Government sets an annual cap on the total volume of greenhouse gas emissions permitted across all regulated sectors. That cap falls each year. Organisations subject to the scheme must hold allowances to cover their emissions, one allowance per tonne of CO2 equivalent, and surrender them annually. If they emit less than their allocation allows, they can sell surplus allowances. If they emit more, they must buy additional ones from other participants or at auction.

The system creates a financial cost for carbon, with prices determined by supply and demand within the scheme’s rules. That price signal is the point of the whole thing: making high-carbon production more expensive, and low-carbon production relatively more attractive.

Which Sectors Are Covered?

Coverage is based on installation type and technical capacity thresholds, not business size. The regulated sectors are:

• Power generation, electricity generators and heat producers above set capacity thresholds
• Energy-intensive industry, including steel, cement, aluminium, glass, ceramics, paper and board, and oil refining
• Aviation, UK domestic flights and routes to the European Economic Area
• Offshore oil and gas, being phased in from 2026

If your site falls within those categories and meets the relevant thresholds, you are a regulated participant. If not, you are not, though that does not mean the scheme is irrelevant to you.

How Carbon Prices Feed Into Energy Bills

Most UK businesses are not directly regulated under the UK ETS, but they pay carbon costs all the same. Power generators covered by the scheme must hold allowances for the emissions from electricity production. That cost is built into the wholesale price of electricity and passed through to consumers.

In the run-up to 2022, UK ETS allowance prices rose sharply, peaking above £70 per tonne of CO2e. Prices pulled back significantly through 2023, settling in the £30-£45 range through 2024 and into 2025. The longer-term direction is widely expected to be upward, the cap tightens on a fixed schedule, free allocation to industry is being phased down, and demand for allowances from the aviation and offshore sectors will grow.

For businesses with significant electricity load, this structural trend matters. Every rise in carbon prices feeds through, with some lag, into power costs. It is one of several reasons why managing energy procurement actively, rather than simply rolling contracts, becomes more valuable over time.

Free Allowances and Why They Matter

Not all allowances are auctioned. Some are allocated free of charge to certain industrial sectors, particularly those at risk of carbon leakage, the scenario where businesses move production abroad to countries without carbon pricing, achieving nothing on global emissions while hollowing out UK industry.

Free allocation has always been a political compromise as much as an economic one. The amounts are calculated on the basis of benchmark efficiency standards: the more efficient your operation relative to industry norms, the larger share of free allowances you receive. The volumes are also being reduced over time, what was a generous cushion in the early years of the scheme is shrinking, and covered operators will need to buy a greater share of their allowances at auction in the years ahead.

For directly regulated operators, understanding your free allocation, how it is calculated, and how to plan around the reduction trajectory is a meaningful commercial exercise.

The Link to Carbon Reporting

For businesses required to report under the Streamlined Energy and Carbon Reporting (SECR) framework or other mandatory disclosure schemes, the UK ETS provides useful context for interpreting your figures. The carbon intensity of the electricity you buy, your scope 2 emissions, is directly linked to the generation mix on the grid, and the cost of carbon in that generation mix is shaped by ETS prices.

As the UK grid decarbonises, the carbon intensity of purchased electricity falls. That is good news for SECR reporters: the same volume of electricity consumption results in fewer reported emissions over time. But the cost of producing that electricity does not necessarily follow the same trajectory, embedded carbon costs in power prices can remain elevated even as the grid gets cleaner.

Our post on carbon reporting requirements for 2026 covers the disclosure side of this in more detail.

Compliance if Your Site Is Covered

If you operate a regulated installation, your obligations are specific and non-negotiable. You need an approved monitoring plan, accurate emissions monitoring and reporting throughout the year, and sufficient allowances surrendered to the Environment Agency by 30 April each year.

Penalties for failing to surrender allowances run to £100 per tonne of shortfall, and your installation is named in the public compliance register. For a site emitting tens of thousands of tonnes, getting this wrong is expensive.

For businesses with both UK and European operations, the two schemes now run entirely independently. Post-Brexit, UK allowances cannot be used to meet EU ETS obligations, and vice versa. Businesses operating across both jurisdictions need to manage two separate carbon positions. For the full scope of obligations as a regulated participant, the official guidance is the starting point: UK Emissions Trading Scheme, GOV.UK.

What Businesses Should Take Away

For the minority of businesses directly regulated under the UK ETS, compliance is the immediate priority. For businesses outside those sectors, the scheme still shapes the cost environment, and in a measurable way.

Carbon pricing is structural. It is not going away, and the government’s stated trajectory is a tightening cap and higher prices over the medium term.

The practical response is the same either way: manage consumption, procure supply efficiently, and understand what is actually driving your bills. Businesses that treat energy as a fixed overhead will increasingly find themselves paying more than they need to as carbon pricing embeds itself further into UK electricity markets.

Catalyst works with UK businesses on energy procurement and cost management. If you want to understand what the UK ETS means for your bills, or how to approach your supply contracts in light of where carbon prices are heading, get in touch.

Speak to Catalyst about your energy costs →