Telecommunications

Three UK sustainability score: 41/100

41/100
Below expectations-5 since last review
14th of 19 in Telecommunications

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About Three UK

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 ↗

Our verdict

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. Companies can never pay for anything about their own score. Last verified May 2026.

That places Three UK joint 384th of 934 companies scored, and 14th of 19 in Telecommunications.

The ten questions

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).

What's missing

Where Three UK lost points

For each question that lost points, the evidence our public rubric looks for that we didn't find.

  • 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 targets7/10Its targets aren't validated by the Science Based Targets initiative.
  • 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.

The calculation

How is Three UK's SINK score calculated?

Same ten questions for every company. No private weighting.

SINK = (0.3 × Base + 0.7 × Performance) × Scale
Industry base impact
Telecommunications sector ceiling.
55 / 100
Performance score
Sum of the ten questions, each scored 0 to 10.
48 / 100
Raw score
Weighted average before scale penalty.
(0.3 × 55) + (0.7 × 48) = 50.1
Scale penalty
Multiplier based on total emissions. Bigger polluters lose more.
× 0.82
Final score
Rounded. Below expectations.
41 / 100
Where the evidence comes from

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.

[1]Self-reported
Three UK Environmental Commitments
Ongoing
Q1Q3Q4Q5Q6Q8Q9
View →
[2]Self-reported
CK Hutchison Group Greenhouse Gas Reporting Criteria 2024
2024
Q1Q2
View →
[3]Independent source
Ditch Carbon — CK Hutchison Group Telecom Holdings
Unknown
Q1Q2
View →
[4]Independent source
CKHGT CDP Supplier Engagement Assessment
2025
Q2Q8Q9
View →
[5]Public record
Three UK and Ericsson Smart Sustainable Networks Press Release
2024Archived copy from 2025-09-10: the original link no longer opens for us.
Q3
View →
[6]Self-reported
CK Hutchison Chairman 2025 ESG Message
2025
Q3
View →
[7]Self-reported
CK Hutchison Group Sustainability Strategy
Unknown
Q5Q6
View →
[8]Self-reported
CK Hutchison Group Sustainability Reports
Ongoing
Q9
View →
[9]Public record
Vodafone and Three Merger Completion Announcement
2024
Q10
View →

If you believe a source has been misread or a newer version exists, submit a challenge.

For Three UK

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    Three UK: SINK sustainability score 41/100.

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Three UK in context

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 14th of 19.

14/19
Three UK's rank
47
Industry average
17
Industry low
60
Industry high
See all 19 in Telecommunications →
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