greenturtles.co.uk
GreenTurtle Standard v1 · published 4 Sep 2026

Every figure, traced to how it was made.

A carbon method for vehicle fleets and business travel. You self-assess against a published method, and every certificate carries a public link showing which figures were measured, which were estimated, and which rest on a default.

Self-assessed · not an audit DESNZ factors, published Fleet + business travel
greenturtles.co.uk
Gold
Self-assessed · 2026
GreenTurtle Standard v1
greenturtles.co.uk/verify/GT-4K29-7T11
Why the mark exists

Your customers are asking. Most fleets cannot answer.

25 Feb 2026

The UK Sustainability Reporting Standards were published. Smaller businesses are not directly in scope — but every customer that is will need value-chain data from you. Source

37%

of medium-sized UK businesses had been asked for carbon data by a customer in the previous 12 months, on British Business Bank research. Source

−26%

The UK electricity conversion factor fell about 26% in the 2026 DESNZ update — a grid and methodology change, not a fleet reduction. The Standard makes the difference visible. Source

The four honest choices

Where the numbers can go wrong, we say so on the face of it.

Distance

Contracted, odometer, or a default

Every vehicle's distance is one of three things, and the certificate says which. Where nothing is known we use 8,000 miles — named, amber, and counted.

Powertrain

An EV is not zero

Battery-electric vehicles use the DESNZ per-km factor for grid electricity. We say zero tailpipe, and we count the charging.

Factors

Published, not proprietary

DESNZ conversion factors, stated by year. When a factor moves — the 2026 electricity factor fell about 26% — the change is shown separately from your operations.

Trend

No trend without a baseline

Year-on-year change is withheld until a snapshot around twelve months old exists. Until then the certificate reads: baseline is building.

8,000 miles, when nothing is known
A default is never silent. An EV is not zero. And there is no trend until there is a baseline to measure it from.
Tiers

Four tiers, each one labelled self-assessed.

Tiers are set by the battery-electric share of your fleet distance over the reporting period. The mark you display always carries the qualifier and the verify code — so anyone reading it knows exactly what it is worth.

See the thresholds
BronzeSelf-assessed
< 20% battery electric
Measured and published.
SilverSelf-assessed
≥ 20% battery electric
Transition under way.
GoldSelf-assessed
≥ 40% battery electric
Two fifths electric.
PlatinumSelf-assessed
≥ 60% battery electric
Majority electric.
Honesty page

Sometimes you need an audit, not a self-assessment.

If a contract requires third-party verification or GHG Protocol assurance, the GreenTurtle Standard is not the right instrument, and we will say so. We have written the comparison down.

Read what we are not