Insights · Decarbonisation · EU MRV
Before Europe could put a price on shipping's carbon, it had to measure it. EU MRV is that measuring stick — the rulebook that makes large ships using EEA ports count, report and independently verify their greenhouse-gas emissions, year after year.
For most of its history, shipping's contribution to climate change was a number nobody had to publish. Fuel was bunkered in one port and burned somewhere over the horizon, and emissions went largely uncounted. The EU MRV regulation set out to change that — not by taxing or capping emissions, but simply by making them visible. It is the foundation on which every later climate rule for European shipping has been built.
MRV stands for Monitoring, Reporting and Verification. Adopted as Regulation (EU) 2015/757, it requires shipping companies to monitor and report the greenhouse-gas emissions and a set of related operational data — fuel consumption, distance sailed, time spent at sea, cargo carried and transport work — for large ships calling at ports in the European Economic Area. The data is collected per ship, per calendar year, checked by an independent accredited verifier, and submitted through the EU's THETIS-MRV reporting system, after which aggregated figures are published.
The headline threshold is 5,000 gross tonnage. Since the first reporting year on 1 January 2018, ships of 5,000 GT and above have had to monitor their emissions on voyages to, from and between EEA ports. The obligation falls on the shipping company — the registered owner or whichever organisation has assumed responsibility for the ship's operation — rather than the master.
The reach of the rule is deliberately practical. It does not matter what flag a ship flies; what matters is that it uses European ports. A vessel registered far outside the EU still falls within MRV the moment it loads or discharges at an EEA berth. That same flag-blind logic is why Marifest keys every record to a hull's permanent IMO number rather than its name or flag.
MRV began as a CO2-only, large-ship-only measure. As the EU prepared to bring shipping into its carbon market, the regulation was amended so that the data it gathered would match the data the market needed to price. Two changes matter most.
From 1 January 2024, the scope was extended beyond carbon dioxide to also cover methane (CH4) and nitrous oxide (N2O) — two greenhouse gases that matter especially for LNG-fuelled and certain other ships. From 1 January 2025, smaller vessels were drawn in: general cargo ships between 400 and 5,000 GT, and offshore ships of 400 GT and above. The 5,000 GT threshold still governs the main reporting obligation, but the 400 GT extension brings a tier of smaller cargo and offshore tonnage into monitoring for the first time.
| From | Gases covered | Ships in scope |
|---|---|---|
| 1 Jan 2018 | CO2 | Ships ≥ 5,000 GT on EEA voyages |
| 1 Jan 2024 | CO2 + CH4 + N2O | Ships ≥ 5,000 GT (unchanged threshold) |
| 1 Jan 2025 | CO2 + CH4 + N2O | + General cargo 400–5,000 GT and offshore ≥ 400 GT |
Read down the table and the design intent is clear: start narrow and certain, then widen as the system proves itself. As of 2026, all three steps are in force, and the smaller-vessel and additional-gas obligations are part of normal annual reporting.
The third letter of MRV is the one that gives the data its weight. A company cannot simply self-declare a number. Instead it follows a defined cycle: first it draws up a monitoring plan describing exactly how each ship's emissions and activity will be measured; then it monitors per voyage and across the year; then it compiles an emissions report.
That report is handed to an accredited independent verifier, whose job is to test whether the figures are complete, consistent and reliable. Where the verifier is satisfied, it issues a Document of Compliance for the ship — the formal evidence, carried on board and recorded in the system, that the year's reporting obligation has been met. Because the same verified dataset is reused downstream, an error caught at this stage is an error kept out of the carbon market.
The monitoring, reporting and verification of CO2 emissions should be regarded as a first step in a staged approach to reducing greenhouse-gas emissions. Regulation (EU) 2015/757
MRV does not, on its own, charge a ship anything for its emissions. Its power is that it produces a single, audited, comparable record of what each ship actually emits — and that record is exactly what the rules with teeth depend on. The EU Emissions Trading System for shipping uses MRV data to determine how many emission allowances a company must surrender, and FuelEU Maritime draws on the same monitored fuel and energy data to police the greenhouse-gas intensity of the fuel a ship burns.
This is the "measure first, regulate later" approach in action. It also sits alongside operational measures such as the IMO's Carbon Intensity Indicator, and it complements the older environmental rulebook set out under MARPOL. For anyone screening a fleet's regulatory standing, MRV is where the emissions story begins.
On Marifest, the same vessel identity that anchors a ship's specifications and ownership chain — its IMO number, gross tonnage and ship type — is what tells you, at a glance, whether a hull is the kind of ship MRV expects to be reporting. You can search any of 97,000+ vessels by name or IMO number and read the full file, then cross-check its sanctions and compliance standing in one place.
How Marifest helps
MRV duties hang on a ship's gross tonnage, type and use of EEA ports — facts that live in the vessel file. Marifest pulls those facts together so you can see at a glance which ships a fleet must report, and check their standing alongside sanctions screening.
Each vessel file shows gross tonnage and ship type, the two facts that decide whether a hull crosses the 5,000 GT or 400 GT MRV thresholds.
Records are anchored to the permanent IMO number, so a rename or reflagging never breaks the link between a ship and its reporting history.
The MRV duty falls on the company. Marifest ties each hull to its owner, manager and operator so you know who carries the reporting obligation.
Read a vessel's emissions-regime relevance next to its sanctions verdict across OFAC, EU, UN and UK lists — one file, one screen.