Insights · Decarbonisation · FuelEU Maritime
FuelEU Maritime does not tax carbon directly. Instead it caps the carbon intensity of the energy a ship burns — and then tightens that cap, step by step, until only near-zero fuels can clear it. It is the rule that decides which fuels still have a future.
Most carbon rules tax emissions after the fact. FuelEU Maritime works the other way round: it sets a ceiling on how carbon-intensive the energy you use is allowed to be, and lowers that ceiling every five years. The genius — and the bite — is in the metric. By measuring greenhouse-gas intensity rather than total tonnes, the regulation pushes owners towards cleaner fuels regardless of how much they sail, and it leaves them free to choose how they comply. It sits alongside the EU Emissions Trading System as the second pillar of the EU's maritime climate package.
The regulation applies to ships of 5,000 gross tons and above, regardless of flag, when they call at ports in the European Economic Area. It captures:
Crucially, the intensity is calculated well-to-wake — counting the emissions from producing and transporting the fuel as well as burning it. That closes the loophole of a fuel that looks clean at the funnel but is dirty to make, and it is why FuelEU rewards genuinely low-carbon energy rather than book-keeping.
The limit is expressed as a percentage reduction from a 2020 reference intensity, and it tightens in steps:
| From | Reduction vs 2020 |
|---|---|
| 2025 | −2% |
| 2030 | −6% |
| 2035 | −14.5% |
| 2040 | −31% |
| 2045 | −62% |
| 2050 | −80% |
The early years are deliberately gentle — a 2% cut is achievable with a modest blend of biofuel or careful operation. But the curve steepens sharply after 2035, and the 2040 and 2050 steps cannot be met with fossil fuels at all. That long signal is the point: it tells owners ordering ships today which fuels will still be legal across a vessel's thirty-year life.
A ship that exceeds its intensity limit runs a compliance deficit and pays a penalty proportional to the size of that deficit and the amount of energy involved. The regulation also escalates the penalty for a vessel that breaches the limit in consecutive years, so persistent non-compliance becomes progressively more expensive. The penalty is designed to be higher than the cost of simply buying compliant fuel, so that paying to pollute is not the cheap option.
FuelEU does not ask how far you sailed. It asks how clean the energy was — and every five years, the answer it will accept gets stricter. The logic of an intensity limit
Because not every ship can switch fuels at the same pace, FuelEU builds in flexibility. An operator can pool the compliance balances of several vessels, so a ship running on a clean fuel and sitting comfortably under its limit can offset a sister ship that is over. Surpluses can also be banked for future years, and a limited deficit can be borrowed against the next year's balance. This lets a fleet meet the overall target in the most cost-effective way rather than forcing every hull to comply in isolation — a structure that interacts with ownership and operation, since the responsible party is the company that holds the commercial operation of the ship.
FuelEU is one of three overlapping pressures on a ship's carbon performance. The EU ETS puts a direct price on the CO₂ a vessel emits on EU voyages; the IMO's Carbon Intensity Indicator rates operational efficiency A to E; and the IMO's 2030 and 2050 targets set the global trajectory behind all of it. Together they mean a ship's fuel choice is now a compliance question, not just an economic one.
On Marifest, the specifications that drive these calculations — a vessel's type, size and operating profile — sit in every file across 97,000+ vessels. You can read a ship's particulars in the registry, see the operators serving EU ports, and check terms such as well-to-wake in the glossary.
How Marifest helps
FuelEU compliance starts from a ship's particulars and operating profile. Marifest holds those facts for the whole fleet, keyed to the permanent IMO number, so the inputs to the calculation are in one place.
Type, size and gross tonnage — the figures that decide whether a ship is in scope — are recorded for every vessel.
FuelEU obligations fall on the operating company; Marifest resolves the operator and manager behind each hull.
Ports data shows which EU ports a fleet serves — the calls that bring a vessel into FuelEU and EU ETS scope.
FuelEU, EU ETS and CII all read off the same vessel, anchored to its IMO number across the registry.