Carbon Credits 101: A Practical Guide for UK Businesses

21 August 2025

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Carbon Credits 101: A Practical Guide for UK Businesses

As sustainability becomes a core part of doing business, organisations across the UK are looking for credible, cost-effective ways to reduce their environmental impact. One method to consider is carbon offsetting - but how exactly does this work, and how can it support your ESG (Environmental, Social and Governance) strategy? 

A carbon credit represents one tonne of carbon dioxide or equivalent greenhouse gas (CO₂e) that has been either removed from the atmosphere (a removal credit) or prevented from being emitted in the first place (an avoidance credit). These credits are generated by certified projects, such as reforestation, renewable energy, or improved land management, that deliver measurable climate benefits. 

When your business purchases carbon credits, you’re effectively funding these projects to compensate for your own unavoidable emissions, reducing your own net carbon footprint. This is known as carbon offsetting (or carbon compensation). Many businesses also purchase carbon credits outside of direct value chain mitigation, recognising the broad positive impact that can be achieved through investing in high integrity environmental projects. 

How is a Carbon Credit Generated?

There’s a clear sequence of steps that must be followed to generate and leverage carbon credits; each of these helps drive confidence that carbon credits available through the voluntary carbon market are trustworthy and do what they claim to do.

1. Project Design

A project developer identifies an opportunity to reduce or remove carbon emissions such as planting trees (afforestation), capturing methane, or installing renewable energy. They design the project to meet the requirements of a recognised carbon standard (e.g. Verra or Gold Standard), choosing a standardised methodology to calculate emissions reductions and ensure comparability across projects.

2. Baseline and Additionality Assessment

The developer establishes a baseline scenario (what emissions would occur without the project) and proves additionality, meaning the project wouldn’t happen without carbon finance. 

3. Validation by a Third Party

An independent auditor (known as a validation and verification body) reviews the project design to ensure it meets the chosen standard’s criteria. They make sure that the baseline and additionality assessments are accurate to reduce the chance of overestimating climate benefit. 

4. Project Implementation

The project is launched; trees are planted, renewable systems installed, or land management practices improved.

5. Monitoring and Reporting

The project developer monitors the project over time and compiles a monitoring report detailing the actual emissions reduced or removed.

6. Verification

The monitoring report is reviewed by an independent verifier to confirm the accuracy of the emissions data and ensure the project is delivering real climate benefits.

7. Issuance of Carbon Credits

Once verified, the carbon standard issues carbon credits, each representing one tonne of CO₂e reduced or removed. These are recorded in a public registry.

8. Sale on the Carbon Market

The credits can now be sold on the voluntary carbon market to businesses or individuals looking to compensate for their emissions; ownership of the credit is passed from the developer to the buyer.

9. Retirement and Claiming

Once a credit is used to offset emissions, it is retired - meaning it can't be sold again and cannot be double counted. The buyer can now claim the associated emissions reduction in their ESG or sustainability reporting. Buyers do not need to physically take delivery of credits to retire them, as the process can be handled through contracts with credits being retired on behalf of the buyer.

It's not always straightforward to understand how carbon credits are generated in practice. Here are a couple of examples to illustrate how different types of projects can generated credits.

An 'Avoidance' example - Renewable Energy:

Renewable energy projects, such as wind farms, solar installations, or hydroelectric plants, play a key role in reducing global greenhouse gas emissions. But how do these projects translate into carbon credits?

Here's how it works:

Displacing Fossil Fuels

Renewable energy projects generate electricity without burning fossil fuels. When a solar farm replaces coal-fired power generation, for example, it prevents a significant amount of CO₂ from entering the atmosphere. The difference in emissions between the renewable source and the conventional alternative is what forms the basis for carbon credit calculation.

Measuring Emission Reductions

To issue carbon credits, the project must:

  • Establish a baseline scenario - what emissions would have occurred without the project, i.e. in this case if the energy was being generated by fossil fuels instead,
  • Measure the actual emissions from the renewable energy source (typically near zero),
  • Ensure that additionality has been considered - i.e. that the energy generated through this project would have been produced through other, higher-emissions sources had carbon credit revenues not been available to fund this specific project,
  • Calculate the net reduction in CO₂ emissions.

Each tonne of CO₂ avoided becomes a potential carbon credit.

A 'Removal' Example - Afforestation:

Afforestation - the process of planting trees on land that hasn’t been forested in recent history - is a powerful nature-based solution to climate change. These projects actively remove carbon dioxide (CO₂) from the atmosphere, making them a key source of removal-based carbon credits.

Here's how they work:

Capturing Carbon Through Tree Growth:

As trees grow, they absorb CO₂ from the atmosphere through photosynthesis and store it in their trunks, branches, leaves, and roots. This process is known as carbon sequestration. Over time, a well-managed forest can capture and store significant amounts of carbon.

Establishing a Baseline and Measuring Impact:

To generate carbon credits, the project must demonstrate that the carbon removal is:

  • Additional - The forest would not have been planted without carbon finance (i.e. it isn't just a patch of land growing vegetation independently).
  • Quantifiable - The amount of CO₂ removed is measured using scientific models and field data.
  • Permanent - Measures are in place to protect the forest from deforestation, fire, or disease.

baseline scenario is established to show what would have happened without the project (e.g. the land remaining barren or used for low-carbon activities). The difference between this baseline and the actual carbon sequestered by the new forest forms the basis for issuing credits.

Not all carbon credits are created equal. That’s why verification by independent, reputable third parties is essential. 

High-quality carbon credits are issued by internationally recognised standards such as Verra (VCS), Gold Standard, Puro, and others. These standards ensure that projects meet strict criteria for:

  • Additionality - the project wouldn't have happened without carbon finance,
  • Permanence - the carbon savings are long-lasting and protected from reveral,
  • Measurability - emission reductions are quantifiable and based on robust methodologies,
  • Thid-party auditing - independent auditors verify the project's impact before credits are issued.

At SEFE, we go a step further by using independent project ratings from platforms like BeZero and Sylvera. These ratings provide an extra layer of transparency, helping you choose credits that align with your values and risk appetite.

Beyond Carbon: Local and Global Benefits:

Carbon compensation projects don't just have emissions benefits - they often deliver a wide range of co-benefits for communities and ecosystems. Depending on the project, these can include:

  • Biodiversity protection - Preserving habitats for endangered species in the case of afforestation, reforestation, or land use projects
  • Rural livelihoods - Creating jobs and income for local communities, for example through land management or construction of renewable energy assets
  • Health improvements - Some projects, such as the distribution of clean cookstoves, reduce harmful air pollution indoors
  • Education and empowerment - Many projects leverage funding from investors to support community-led development initiatives

By choosing the right carbon credits, your business can support projects that align with your broader ESG goals; not just environmental, but social and ethical too.

At SEFE, we make it simple for organisations to access high-quality carbon credits through our Carbon Offsetting Programme. Here's what sets us apart:

  • Tailored sourcing - We help you find credits that match your budget, values, and sustainability goals.
  • Independent ratings - All credits are assessed by trusted third-party platforms for transparency and credibility.
  • No bundled consultancy - We're not here to upsell, we simply help you make informed choices.
  • Competitive pricing - We offer credits close to secondary market rates, making carbon compensation accessible for businesses of all sizes.

Whether you're just starting your sustainability journey or looking to enhance your ESG credentials, SEFE is here to support you.

Take the First Step Toward Net Zero

Carbon credits are not a silver bullet, but they are a powerful tool for organisations looking to take meaningful climate action today. By supporting verified projects, you can reduce your environmental footprint, meet stakeholder expectations, and contribute to a more sustainable future.

If you would like to hear more on this topic, you can find a recording of our recent webinar on the Voluntary Carbon Market here, with insights from SEFE specialists. 

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