Three UK sustainability score: 41/100
Better than 33% of Telecommunications
Making progress starts at 46. The highest score on SINK is 71.
Limited independent evidence: only two independent sources cover this company. The score may change as more evidence appears.
Three UK is a major UK telecommunications operator offering mobile, broadband, and fixed-line services to approximately 10.6 million customers. Founded in 2001 and headquartered in Maidenhead, it operates as a subsidiary of CK Hutchison Group.
More about Three UK
The company competes in a highly regulated UK telecoms market dominated by larger players.
Founded 2001Head office Maidenhead, United KingdomStaff ~4,500Revenue ~£2.59BWebsite ↗
Three UK lacks entity-level emissions disclosure, relying entirely on parent company CKHGT's group-level data. Carbon footprint, supply chain, and trajectory evidence are absent at the operating company level. Strong renewable electricity commitment (97%) and SBTi-validated targets are offset by no biodiversity policy, minimal waste metrics, and no standalone sustainability reporting despite £2.59bn revenue.
Three UK scores 41/100 (Below expectations) on SINK's independent climate assessment, scored from public data only. Scores are free. Nobody can pay to change a score, speed it up or hide it. Last verified May 2026.
That places Three UK joint 390th of 1,023 companies scored, and 13th of 19 in Telecommunications.
What is Three UK doing well, and where does it fall short?
Strongest on Controversies & Red Flags and Energy Source (8/10, 7/10). Weakest on Nature & Biodiversity Impact and Water Impact (2/10, 3/10).
Where Three UK lost points
For each question that lost points, the evidence our public rubric looks for that we didn't find.
What would raise this score
- Its effect on natureAssess its effect on nature and publish a basic environmental policy.
- Its effect on waterMonitor its water use and take measures to reduce it.
- Emissions from its own operationsPublish full Scope 1 and 2 figures worked out to the GHG Protocol.
Every question that lost points
- Emissions from its own operations4/10No full Scope 1 and 2 figures worked out to the GHG Protocol.
- Emissions from its supply chain5/10Most of its supply-chain (Scope 3) emissions aren't measured.
- Whether its emissions are falling4/10No evidence of a year-on-year fall in its total emissions.
- How clean its energy is7/10Less than 90% of its energy shown to be renewable.
- Its effect on nature2/10No assessment of its effect on nature, and no basic environmental policy.
- How it uses materials and handles waste4/10No measurable waste or recycling targets reported publicly.
- Its effect on water3/10No monitoring of water use, or no measures to reduce it.
- Its climate targets7/10No validated long-term net zero target.
- How openly it reports4/10No dedicated sustainability role, board oversight or public report.
A score changes when the evidence does. We use new published evidence at the next rescore. Anyone can send us new evidence, free. How to send it.
How is Three UK's SINK score calculated?
Same ten questions for every company. No private weighting.
SINK = (0.3 × Base + 0.7 × Performance) × ScaleHas Three UK's score changed?
Three UK's score has been reviewed 3 times and currently stands where it started, at 41.
- 41 → 417 November 2026
Limited-evidence banner: 2 independent parties once company-published sources are not counted (owner ruling 2026-11-07). Score unchanged.
- 41 → 417 November 2026
Correction, 7 November 2026: removed an unsourced emissions figure. Score unchanged.
- Scored 414 April 2026
Initial score at platform launch
What evidence is Three UK's score based on?
9 sources used in this assessment. All publicly available. Each row shows which of the ten questions it informed.
56% of them were published by Three UK itself; the rest come from independent sources.
Scored on 4 April 2026 under an earlier version of our method. We're re-checking it under the current method.
If you believe a source has been misread or a newer version exists, submit a challenge.
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How does Three UK compare with other telecommunications companies?
Where Three UK sits among telecommunications peers.
Among the 19 major telecommunications brands we've scored, Three UK sits 13th of 19.
Who scores higher in Telecommunications?
The 3 companies in the sector scoring nearest above Three UK.
altafiber reports Scope 1+2 emissions with third-party verification and a 40%-by-2030 target, but Scope 3 (73% of footprint) is screened only once per 3–5 years with no supplier engagement.
See the breakdown →Airtel Africa discloses emissions data aligned with GHG Protocol but lacks third-party verification.
See the breakdown →BT Group discloses operational emissions comprehensively with third-party assurance and has achieved 52% absolute Scope 1+2 reduction.
See the breakdown →Which companies moved this week, and why.
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