Version v2.5.16, last changed 17 October 2026.
This is every rule we use to score a company. If you want the short version first, start with how scores work.
Score = (0.3 × starting point + 0.7 × questions) × size multiplierThe industry starting point and the ten questions are both out of 100. We take 30% of the first and 70% of the second. The industry matters, but what a company does matters more.
Then we multiply by the size multiplier, which is between 0.60 and 1.00. We round once, at the end, to a whole number.
This reads the company’s current score from our database, so it always matches its company page.
Electronics / Hardware starts at 40.
The ten question scores added up, out of 100.
30% of the starting point plus 70% of the questions.
Apple Inc. reports about 15.3 million tonnes a year, so 30% comes off.
57.5 × 0.70 ≈ 40. Below expectations.
Every company gets the same ten questions. The first seven are about physical harm. The last three are about whether the company is improving, and whether it can be held to account.
Each question has four fixed points: 0, 3, 6 and 10. A score in between shows how close the company is to the next point. Energy bills, supplier records and water bills count at every level, so you don’t need formal reporting to score well.
Does it measure and publish the emissions from its own sites and vehicles (Scope 1 and 2)?
Does it know the emissions in its supply chain and from its products in use (Scope 3)?
Are its emissions actually going down, year on year?
How much of its energy comes from renewable sources?
What does it do to forests, land and wildlife?
Does it reuse and recycle, or make, use and throw away?
How much water does it use, and does it pollute any?
Does it have targets backed by science, and does it cut before it offsets?
Does it publish what it does, and who at the top answers for it?
Any pollution cases, fines, or lobbying against climate action?
Each industry gets a starting point out of 100. It reflects the harm its core work does, whoever does it. Higher means less harm. Tap any row to see why.
We add industries as we score new kinds of company. Our editors set each starting point, and you can challenge any of them with evidence.
What matters to the planet is total tonnes, whatever the company’s size. So we multiply by a figure set by the company’s total yearly emissions. That’s its own operations (Scope 1 and 2) plus its supply chain and products in use (Scope 3).
We still score the company, with a 0.70× multiplier. That’s 30% off, the same as a company emitting 10 to 50 million tonnes.
We use two labels, and never claim more than we know. “Not retrieved” means our search didn’t turn up a figure we could cite. It doesn’t mean the company publishes nothing. “No public figure” is only used once we’ve confirmed the company doesn’t publish one.
Very small companies are the exception: fewer than 250 staff and revenue under £50 million. For them we treat the figure as an estimate and don’t apply the 0.70×. The exception never applies when we don’t know the revenue. It also never applies to heavy industries (oil and gas, mining, coal, chemicals, cement and glass) or to financial firms. A financial firm’s emissions sit in what it funds, whatever the size of its offices.
In some industries most emissions sit in the supply chain or in products in use. There, a total that leaves out Scope 3 is treated as incomplete. The multiplier is capped at 0.70×, and a person checks the score before it goes live.
We check every total against a ceiling for its industry, to catch figures that can’t be real. If a total is over the ceiling, we throw it out. The exception is a figure in the company’s own report, where the report says an outside party checked it. We use that figure, and a person checks the score before it goes live.
Water companies have their own industry, starting at 40. Their size multiplier uses only their own operations’ emissions (Scope 1 and 2), so reporting the supply chain in full can’t push a company into a bigger deduction. We credit supply chain reporting in question 2 instead.
A financial firm does most of its harm through what it lends to, invests in and insures (financed emissions). If a bank publishes its financed emissions on the standard basis (PCAF) in its own report, we use that figure. If it doesn’t, its multiplier is capped at 0.70× and a person checks the score before it goes live.
Jewellery and watch makers have their own industry, starting at 40, level with electronics. Gold, diamonds and gemstones take a lot of mining, but the products are made in small numbers and last for decades. Smartwatches stay with electronics, leather goods with clothing, and perfume with consumer goods.
We score every company the same way, and the questions ask a lot. Most companies land between 30 and 60, and scores above 75 are very rare. A score of 60 or more takes real leadership: checked data, science-based targets and open governance.
A full score cites at least 8 live sources. No more than 70% of them can come from one website. At least 3 must come from outside the company: national emissions registers, CDP, the Science Based Targets initiative, official filings, journalism or standards bodies. The company’s own website, microsites and press releases don’t count as outside sources.
We don’t use websites that repackage other people’s figures (data aggregators). You can’t trace their numbers back to where they came from. Every link must be live when we publish.
An audited annual report filed at Companies House counts as one outside source. We discount a company’s own website because nobody checked it. A filed report has been audited and lodged with the official registrar. It counts once per company, however many filings we cite, and it’s never enough on its own.
Some companies file their report as a scanned picture. We read those with text recognition (OCR), so their emissions figures can be quoted and cited like any other source. We won’t mark a company down because we couldn’t read its file.
Some organisations must send measured data to a public body they don’t control. UK universities and the HESA estates return were the first case. When a record cites a return like that, up to 85% of sources can come from one website. The publisher also counts as an outside source.
Some companies publish too little to reach 8 sources from 3 outside parties. If every quality check still passes, we publish the score as provisional. The page carries a banner with the real counts, and a note on what’s missing and what would close the gap. We never pad the source list.
Faulty evidence still blocks a score at any level: a dead link, a data aggregator, or a score that rests on one website. A banner can’t fix those.
Public evidence is the right place to start, because anyone can check it. Its weakness is that a company doing good work quietly scores below one doing average work loudly.
Scoring low on something you do well? Here’s how companies can show us their evidence →
A company’s industry sets its starting point, the questions’ detail and the companies it’s compared with. One mistake there becomes three. So we look it up from outside sources before we score, in this order:
If the sources agree, we score the company. If a source of the same or higher rank disagrees, we hold the company for a person to look at. A lower-ranked source that disagrees is noted, and doesn’t hold anything up.
We classify a company by what it makes, whatever sector it sells to. A maker of ground equipment for airlines or carmakers is scored on its own products. It isn’t scored on the emissions of the planes or cars.
Every company page shows where its industry came from, the code that source used, and the date. If you think it’s wrong, you can see exactly how we got there.
This badge is for companies whose main business removes more greenhouse gas than it creates. It sits next to the score and doesn’t change it. A company needs all three:
Companies can’t pay for this badge.
Every score starts as “Pending review”. That means it’s live, and anyone can challenge it.
The next level is “Verified”. An editor would give it once a score has held steady over time, with evidence from readers behind it. No score has reached Verified yet.
Verified is never automatic. A vote count can’t trigger it, and a Verified score can still be challenged.
Every question on every company page has a Challenge button. Pick the score you think is right, add a link to your evidence, and send it. It’s free, and anyone can do it.
Challenges are public. If the evidence supports a different score, we change it, credit you, and log the change on the company’s page for good. A challenge can move a score up or down.
We’d rather be corrected than stay wrong.
Changes that affect scores, newest first. A score only moves when that company is re-scored, and every move is logged on its page.
Every company page shows its own working: the starting point, the ten question scores with evidence and sources, and the size deduction.