For many people, the bank they choose to use depends on its reputation, trustworthiness, customer service and the interest rates offered.
Most people will open an account without stopping to think about what their deposits are being used for, or why they are able to offer such strong savings rates.
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“Worryingly, our latest research has shown that far from making progress in this area, many major banks are instead choosing to invest ever larger sums into environmentally damaging industries.”
The worst fossil fuel financing banks
Chase
The worst bank in terms of climate impact is Chase, a subsidiary of JP Morgan Chase, the world’s leading financier of fossil fuels according to the Banking on Climate Chaos by Rainforest Action Network.
The bank contributed around $53.4 billion (£39.79 billion) in 2024 alone, $15 billion (£11.16 billion) more than in the year prior, the report said.
Among the 16 banks Which? examined, Chase received by far the lowest climate policy score of just 10% as its coal, oil and gas policies mean firms actively expanding their fossil fuel operations can approach the bank.
Despite its poor climate policy ranking, Chase stands out to retail customers thanks to the high interest rates offered by its savings accounts. Its easy-access saver with boosted rate offers 4.5% interest, inclusive of a 1.94% bonus for the first 12 months, making it the top easy access saving account on the market.
A spokesperson for JP Morgan Chase (parent company of Chase) said: "We are a leading global financier of diversified energy sources to power the global economy, including providing clean energy financing with a target of $1 trillion for climate initiatives and sustainable resource management by the end of 2030."
Santander
The second-worst bank for climate impact is Santander, which received a climate policy score of 28% by Which’s analysts, as its policies allow it to support firms developing new fossil fuel projects.
Santander also publishes less data than other big banks on its climate impact, according to Which?, while it also eased restrictions for oil and coal firms to receive corporate finance.
The bank contributed $17.3 billion (£12.87 billion) to the fossil fuel industry in 2024.
A spokesperson for Santander said: “As a global financial institution, Santander understands the role we play in supporting clients in their transition, fostering inclusive and economic growth for communities and businesses. Santander is supporting companies in their transition to a low-carbon economy and has been financing the build-out of renewable energy capacity for decades.”
HSBC (and First Direct)
HSBC, including its subsidiary First Bank, invested $16.2 billion (£12 billion) in fossil fuels last year, and received a climate policy score of 29% from Which?.
In 2024, the bank increased its fossil fuel funding by $4.2 billion (£3.6 billion) despite commitments not to. Which? also says its coal policy is rife with exemptions, allowing polluting firms to access finance from HSBC.
MoneyWeek has contacted HSBC and First Direct asking for comment.
Barclays invested $35.4 billion (£26.34 billion) in the fossil fuel industry last year, around $12.6 billion (£9.36 billion) more than it did in 2023. It received a Which? climate policy score of 35%.
In terms of climate impact restrictions, the bank only bars clients that generate over 30% of their revenue from thermal coal mining or power from accessing finance from them, while also barring some coal developers.
It is also the only European bank in the Banking on Climate Chaos “Dirty dozen” list of top fossil fuel financiers globally, ranking tenth.
A spokesperson for Barclays said: “Barclays is committed to its ambition to be a net zero bank by 2050 by working with our clients on their transition, financing clients’ transition and scaling climate tech. Many of the economies we serve still depend on conventional energy for reliable and affordable power as they transition to renewables. Barclays is providing the finance to meet current energy needs while financing the scaling of clean energy, delivering against our target to facilitate $1 trillion of Sustainable and Transition Finance by 2030.”
The others
The following banks scored much higher for their climate policy than the previous four, but they still have room for improvement according to Which?.
Lloyds Banking Group (which includes Lloyds, Halifax, and Bank of Scotland) managed to make a cut in its fossil fuel financing last year, contributing a total of $1.6 billion (£1.19 billion), $673 million (£500.68 million) less than in 2023. This being said, it did increase oil and gas expansion finance by $572 million (£425.48 million). It scored a climate policy score of 45%.
NatWest (including Royal Bank of Scotland) received a climate policy score of 46% thanks to its more transparent climate reporting and strong deforestation policies. It did, however, increase its fossil fuel financing by $615 million (£457.32 million) in 2024, to $2.7 billion (£2 billion).
Finally, Danske Bank only contributed $1.3 billion (£966.77 million) to fossil fuel financing in 2024, less than most other large banks. It achieved a climate policy score of 47% thanks to strong fossil fuel policies, but is held back on the Which? ranking by “weak” commitments to the transportation, storage, and processing of oil and gas.
MoneyWeek has contacted Lloyds Banking Group, NatWest and Danske Bank asking for comment.
A list of the worst fossil fuel financing banks according to Which? can be found below.
Bank | Financing 2024 | Fossil fuel policies | Agricultural policies | Targets | Transparency | Climate Policy Score |
|---|---|---|---|---|---|---|
Chase | $53.5 billion | 5% | 8% | 38% | 17% | 10% |
Santander | $17.3 billion | 16% | 22% | 63% | 50% | 28% |
HSBC | $16.2 billion | 25% | 14% | 50% | 50% | 29% |
Barclays | $35.4 billion | 23% | 33% | 63% | 83% | 35% |
Lloyds | $1.6 billion | 34% | 54% | 63% | 67% | 45% |
NatWest | $2.7 billion | 27% | 59% | 75% | 83% | 46% |
Danske Bank | $1.3 billion | 49% | 19% | 75% | 67% | 47% |
Source: Which?, October 2025
The best eco-banks
Out of the 16 banks analysed by Which?, only two impressed their researchers enough to be endorsed by the company.
The Co-Operative Bank
The Co-Operative Bank was awarded an endorsement by Which? thanks to having no exposure to fossil fuels in its banking activities, while also having set itself high ethical standards.
The bank’s policy is that it refuses to fund “the unsustainable harvest of natural resources”, which includes timber, fish and palm oil, while also being transparent in measuring and disclosing its emissions.
Triodos Bank
Triodos Bank also won the approval of Which? by its zero exposure to fossil fuel financing and its high transparency.
The bank publishes the entirety of its loan portfolio online so customers can examine precisely what their deposits are helping to finance.
Its focus on renewable energy is commended by Which?, while it also scores highly for policies preventing deforestation. Triodos also has clear climate targets for 2030 and 2035 which are validated by the independent Science Based Targets initiative (SBTi).
The ones that just missed out
While Which? only awarded two eco-endorsements this year, some other well-known banks just missed out on receiving one.
Allied Irish Bank (AIB), Bank of Ireland, Metro Bank, Nationwide Building Society, Starling Bank, and TSB are all on the right track towards limiting their exposure to the fossil fuel industries but still have some work to do to minimise their involvement, Which? said.
A lack of concrete data also holds Monzo back from receiving an endorsement as it does not have any specific climate policies and targets apart from achieving net zero by 2030, Which? said. However, Monzo does not use its customer’s deposits to provide financing to any firms, including fossil fuel companies.
Finally, Nationwide Building Society also came close to receiving an eco-endorsement from Which? but just missed out as Virgin Money, which it acquired in 2024, has some low exposure to the fossil fuel industry, accounting for around 1% of its business lending.
A spokesperson for Nationwide/Virgin Money said "environmental and climate consciousness are core to Nationwide’s strategy and align to our mutual purpose for the good of our communities and wider society". They added that following the acquisition of Virgin Money, they are "exploring how we bring the benefits of business banking to more customers across the Group over time, but our ambition to minimise our environmental impact will not change".
The spokesperson added: "We have internal controls and procedures, such as our sensitive sector policy, and are focussed on reducing emissions from our highest emitting business sectors. We do not have direct exposure to businesses generating revenue directly from oil and gas extraction. Indirectly, only around 1% of our business lending is to businesses who provide field services to the oil and gas industry, compared to around 4% to companies enabling the energy transition.”
A spokesperson for AIB said "greening our business" is one of its three strategic priorities and sustainability "is at the heart of everything we do".
They added: "AIB is fast-tracking on our transition to decarbonisation, by reducing our own carbon footprint, by providing quality advice to our customers, by supporting green homes and businesses, and financing large-scale infrastructure like renewable energy projects in Ireland, the UK and internationally. AIB’s €30 billion Climate Action Fund is actively supporting our customers with €19.1 billion of green and transition finance deployed since the fund launched in 2019, including €2.5 billion in the first six months of 2025, representing 36% of all new lending in the period.”
A spokesperson for TSB said: “As a standalone, UK retail bank, customers can take confidence in TSB’s robust, internationally recognised commitments on environmental impact. We are not involved with the environmentally harmful practices that Which? is investigating.”
