Carbon Credits Explained: A Guide for UK Businesses

Carbon credits are the currency of carbon markets — but what are carbon credits, how do voluntary carbon markets differ from the UK emissions trading scheme, and what should UK businesses know before buying carbon credits? This guide provides carbon credits explained in practical terms, covering compliance and voluntary systems, carbon credit schemes UK organisations encounter, and the quality criteria that separate credible purchases from greenwashing risk.

Pair this guide with our carbon offsetting overview for the broader strategic context.

Last updated: 24 June 2026 | Reviewed by Sustainability Editor


What are carbon credits?

A carbon credit is a tradable certificate representing one tonne of carbon dioxide equivalent (CO₂e) either removed from the atmosphere or avoided through an approved project. Credits are issued after verification and retired when used to offset emissions.


Key takeaways

  • Carbon credits operate in two distinct systems: compliance markets (e.g. UK ETS) and voluntary carbon markets.
  • One credit = one tonne CO₂e reduced or removed, but quality varies significantly between projects.
  • UK businesses in covered sectors must comply with the emissions trading scheme — voluntary credits do not substitute for this.
  • Before buying carbon credits, complete reductions first and apply quality criteria: additionality, permanence, verification.
  • UK forestry schemes (Woodland Carbon Code, Peatland Code) offer domestically verified removal credits.
  • See carbon offsetting for how credits fit a broader climate strategy.

What are carbon credits?

Definition

A carbon credit (or carbon offset credit) represents a quantified greenhouse gas benefit — one metric tonne of CO₂ equivalent — from a project that either:

  • Avoids emissions that would otherwise have occurred (e.g. replacing fossil fuel generation with renewables)
  • Reduces emissions from an existing source (e.g. capturing methane from landfill)
  • Removes CO₂ from the atmosphere (e.g. afforestation, direct air capture)

Credits are issued by registries under recognised standards, traded (in voluntary markets), and retired when an organisation uses them to offset its own emissions.

How credits differ from allowances (UK ETS)

Term System Meaning
Carbon credit Voluntary market Offset from a project, purchased voluntarily
Allowance (permit) UK ETS Government-issued right to emit 1 tonne within compliance cap

Businesses outside UK ETS sectors typically encounter voluntary credits. Covered installations must surrender UK ETS allowances — not voluntary offsets — for compliance.


Compliance vs voluntary carbon markets

UK Emissions Trading Scheme (UK ETS)

The UK ETS is the UK’s cap-and-trade emissions trading scheme, administered by DESNZ and the Environment Agency. It replaced UK participation in the EU ETS following Brexit.

Who participates:

  • Power stations and industrial installations above thresholds
  • Aviation (domestic UK flights)
  • Waste incineration (from 2028 under current expansion plans)

How it works:

  1. Government sets a cap on total emissions in covered sectors
  2. Installations receive or purchase allowances
  3. Each year, operators surrender allowances matching their verified emissions
  4. Allowances trade on secondary markets, setting a carbon price signal

UK ETS vs voluntary credits:

Feature UK ETS Voluntary carbon market
Mandatory? Yes, for covered installations No
Units Allowances Project-based credits
Purpose Regulatory compliance Voluntary offsetting, neutrality claims
Price driver Auction + market trading Project type, quality, demand
Use for corporate claims Compliance reporting Carbon neutral / residual neutralisation

Most UK SMEs are not UK ETS participants. They engage with voluntary carbon markets if they purchase offsets.

Voluntary carbon markets

The voluntary carbon markets connect project developers with corporate buyers. Major registries include:

  • Verra (Verified Carbon Standard / VCS)
  • Gold Standard
  • American Carbon Registry
  • Woodland Carbon Code (UK)
  • Peatland Code (UK)

Market value has grown substantially, but quality concerns have prompted integrity initiatives including the Integrity Council for the Voluntary Carbon Market (ICVCM) and its Core Carbon Principles (CCP) label.


Carbon credit schemes UK businesses should know

International programmes

Standard Typical projects Considerations
VCS (Verra) Renewables, forestry, cookstoves Large volume; scrutinise individual projects
Gold Standard Renewables, efficiency, WASH Strong sustainable development criteria
Plan Vivo Community forestry Smallholder focus

UK domestic schemes

Scheme Type Verification
Woodland Carbon Code UK forestry removal UK Forestry Standard compliance
Peatland Code UK peatland restoration IUCN UK Peatland Programme

UK-based credits offer geographic traceability and support domestic nature recovery — relevant for organisations with UK-focused sustainability narratives.

The Carbon Trust recommends rigorous due diligence on any credit purchase, regardless of standard.


Buying carbon credits: a step-by-step process

Step 1: Measure and reduce first

Calculate your carbon footprint and implement reduction strategies before purchasing credits. The SBTi does not permit offsets to meet near-term reduction targets.

Step 2: Define your purchase purpose

Purpose Credit type typically needed
PAS 2060 carbon neutrality Verified avoidance or removal credits
Event offsetting Calculated scope for specific activity
Net zero residual neutralisation Permanent removal credits (SBTi criteria)
CSR / contribution Any verified project — but do not overclaim

Step 3: Set quality criteria

Evaluate credits against:

  • Additionality — project dependent on credit revenue
  • Permanence — durability of carbon storage (critical for forestry)
  • Leakage — emissions displaced, not eliminated
  • Verification — independent third-party audit
  • Registry — credits issued and retired on a public registry
  • CCP label — where available, indicates ICVCM quality threshold

Step 4: Select a procurement route

Route Pros Cons
Direct from registry/project Transparency Requires expertise
Offset broker Convenience, portfolio options Broker fees; variable quality
Integrated service (travel, events) Simple Often opaque project detail

Step 5: Retire and document

Retire credits on the registry so they cannot be resold. Retain retirement certificates and disclose volume, standard, and project type in reporting.


Pricing and market dynamics

Voluntary credit prices vary:

  • Avoidance credits (renewables, efficiency): often £3–£15/tCO₂e
  • Nature-based removals (forestry): £10–£30/tCO₂e
  • Engineered removals (DAC, biochar): £100+/tCO₂e

Price reflects perceived quality, project costs, and demand — not guaranteed climate impact. Always verify project documentation.

UK ETS allowance prices are set by auction and secondary market trading — check current DESNZ published data for compliance cost benchmarks.


Risks and greenwashing considerations

  1. Double counting — buyer and host country both claiming the same reduction
  2. Non-additional projects — credits funding activity that would happen anyway
  3. Reversal — forest fires or harvesting releasing stored carbon
  4. Overstated baselines — projects claiming inflated “business as usual” emissions
  5. Claiming compliance — voluntary credits do not satisfy UK ETS obligations

UK businesses making offset claims must comply with the CMA Green Claims Code. See also what is greenwashing.


UK ETS in more detail

Sectors currently covered

The UK ETS applies to:

  • Power generation — fossil fuel power stations above capacity thresholds
  • Energy-intensive industry — steel, cement, chemicals, and similar sectors
  • Aviation — UK domestic flights and flights from the UK to the EEA
  • Maritime (from 2026, per current government plans) — domestic voyages and UK port stays

Allowance allocation

Installations receive free allowances (to protect competitiveness) and/or purchase allowances at government auction. The cap decreases over time, tightening the carbon budget for covered sectors.

Implications for supply chains

Even if your business is not a UK ETS participant, your suppliers in covered sectors face a carbon price. This cost may flow through to your procurement prices — understanding UK ETS helps interpret supplier cost pressures and carbon surcharges.

UK ETS and net zero

UK ETS drives decarbonisation in the heaviest industrial emitters. Corporate buyers should not confuse ETS compliance by suppliers with their own voluntary offsetting obligations. Your scope 3 includes supplier emissions — engaging suppliers on their decarbonisation plans is more impactful than buying voluntary credits to compensate.


Credit registries and retirement

When buying carbon credits, verify the registry:

Registry Credits
Verra Registry VCS credits
Gold Standard Registry GS credits
UK Land Carbon Registry Woodland Carbon Code, Peatland Code
UK ETS Registry Compliance allowances (not voluntary)

Retirement permanently removes credits from tradable supply. Obtain retirement certificates with unique serial numbers for your records and external reporting.


How carbon credits fit net zero planning

Stage Role of credits
Near-term (to 2030) Reduction through operations — not credits
Medium-term Credits may support carbon neutrality milestones
Net zero date Permanent removal credits for residual emissions only (≤10% under SBTi)

Read carbon neutral vs net zero and create your net zero strategy for the full framework.


Frequently asked questions

What are carbon credits in simple terms?

Certificates representing one tonne of CO₂e reduced or removed by a verified project. Companies buy and retire them to offset emissions they still produce.

What is the UK ETS?

The UK Emissions Trading Scheme is a mandatory cap-and-trade system for energy-intensive industries and aviation. Operators must surrender allowances matching their emissions. It is separate from the voluntary offset market.

Can I use voluntary credits for UK ETS compliance?

No. UK ETS requires surrender of UK ETS allowances, not voluntary carbon credits.

How do I know if carbon credits are legitimate?

Check the registry, verification standard, additionality evidence, retirement record, and whether CCP labels apply. Avoid credits with opaque project documentation.

Are UK Woodland Carbon Code credits good quality?

They provide UK-verified forestry removals with permanence monitoring requirements. Like all nature-based credits, they carry reversal risk — but the standard includes buffer pools and long-term management plans.

Should small businesses buy carbon credits?

Only after reducing emissions where practical. SMEs often achieve meaningful cuts through renewable energy and efficiency before needing credits.


Conclusion

Understanding what are carbon credits — and how they differ from UK ETS allowances — is essential for UK businesses navigating voluntary carbon markets. Buy credits with rigour, retire them transparently, and treat them as a supplement to reduction — not a substitute.

Related guides:


Sources

This article is for general guidance only. It does not constitute legal, financial, or environmental consultancy advice.