EU ETS for shipping: scope, EUA liability, phase-in

What the EU ETS is, and why shipping is now in it

The EU Emissions Trading System is a cap-and-trade market that has priced industrial CO2 since 2005 under Directive 2003/87/EC. A cap is set on total emissions from covered sectors, that cap is converted into a finite number of EU Allowances (EUAs), and each operator must hold and surrender one allowance for every tonne of CO2 it emits. The cap falls every year, so allowances get scarcer, and the price rises until abatement becomes cheaper than buying an allowance. Power plants, refineries, steel and cement have lived inside this market for two decades. Aviation joined in 2012.

Shipping is the latest sector to be pulled in. Directive (EU) 2023/959, published in the Official Journal on 16 May 2023, amends the ETS Directive to add maritime transport with effect from 1 January 2024. The mechanics are identical to the rest of the system: a covered ship’s CO2 emissions are converted into a number of EUAs that the responsible company has to buy on the market (or hold from earlier purchases) and hand back to the regulator once a year. There’s no free allocation for shipping, unlike the partial free handouts some industrial installations still get. Every covered tonne costs real money at the prevailing EUA price.

That price isn’t trivial. Primary auction clearing prices ran from EUR 66.49 to EUR 96.33 in 2023 (average EUR 83.60) and from EUR 49.50 to EUR 75.35 in 2024 (average EUR 64.74), and at full phase-in a single large container ship or tanker can carry a seven-figure annual bill. The carbon cost has stopped being a line item that environmental managers track and become a number that affects voyage economics, charter rates, and which trades a vessel takes. To put a euro figure on your own fleet’s exposure, the EU ETS Shipping EUA Liability calculator converts covered CO2 tonnage and the phase-in factor straight into an allowance count & cost.

The legislative path matters for anyone reading the rules now. The maritime extension came out of the “Fit for 55” package, the EU’s plan to cut net greenhouse-gas emissions 55% below 1990 levels by 2030. Maritime had been outside any binding EU emissions cap until then, monitored under MRV since 2018 but never charged. The 2023 amendment closed that gap. It didn’t create a separate shipping carbon market with its own cap; it folded shipping into the existing single ETS, drawing on the same allowance pool industrial & aviation operators use. A shipping company buying EUAs is bidding against a power utility & a steelmaker for the same instrument, which is why the maritime carbon price tracks the broader EUA price rather than moving on its own supply & demand.

Which ships are in scope, and from when

The headline threshold is 5,000 gross tonnage and above. From 1 January 2024, every cargo ship & passenger ship at or above 5,000 GT that calls at a port in the European Economic Area is in scope, regardless of flag. A Panamanian-flagged bulker, a Liberian tanker, a Marshall Islands box ship: flag is irrelevant. What matters is the GT figure on the tonnage certificate & whether the ship touches an EEA port. The EEA here means the 27 EU member states plus Norway & Iceland, so a Rotterdam-Oslo run is fully internal to the system.

Offshore ships of 5,000 GT and above and general cargo ships between 400 and 5,000 GT entered the monitoring side first. Under Regulation (EU) 2023/957, which amended the EU MRV Regulation to feed the ETS, general cargo ships below 5,000 GT but not below 400 GT (Article 2(1a)) and offshore ships of 400 GT and above (Articles 2(1a) and 2(1b)) have had to monitor and report their emissions from 1 January 2025. That reporting year is the evidence base for a later review: the Commission has to assess by the end of 2026 whether to bring those segments into the surrender obligation, with offshore ships at or above 5,000 GT scheduled to face the obligation from 2027. Until then, the smaller general cargo & offshore fleet reports data without buying allowances.

The directive carved a temporary derogation for passenger ships (other than cruise ships) operating on routes to small islands, and for certain ice-class ships, recognizing that thin-margin lifeline ferries & winter Baltic trades faced disproportionate cost. Those derogations are time-limited & narrow; for the mainstream commercial fleet, the 5,000 GT rule is the line that matters.

Two outermost-region & island derogations are worth knowing because they shaped where the early cost fell. They are derogations from the surrender obligation, not exclusions from scope, and they run to 31 December 2030: member states with islands could request one for some passenger services connecting those islands to the mainland, and routes to & from the EU’s outermost regions got similar treatment. These weren’t general escape hatches; they were targeted at routes where there’s no commercial alternative to the ferry and the carbon charge would have landed on a captive local population rather than on a tradeable freight market. They expire, after which those routes fold into the mainstream regime. The cruise sector, by contrast, got no island-route relief: a 5,000 GT-plus cruise ship calling at an EEA port pays from 2024 like any other passenger ship.

The threshold is deliberately set at gross tonnage rather than deadweight or cargo capacity. GT is a volume measure already on every ship’s tonnage certificate, audited by class & flag, and hard to game. Tying scope to GT means the boundary doesn’t move with how heavily a ship happens to be loaded on a given voyage, and it lines the ETS up with the MRV threshold that’s used the same 5,000 GT cutoff since 2018. A ship that drifts across the 5,000 GT line through a conversion or re-measurement changes its ETS status, which is one reason owners contemplating a lengthening or tonnage-affecting modification now check the carbon consequence alongside the class one.

Which voyages count, and at what share

The geographic scope is where the maritime ETS departs from the rest of the system. A power plant’s emissions all happen inside the EU. A ship’s don’t. So the directive splits coverage by voyage type, charging 100% on emissions inside the EEA and 50% on emissions to or from the outside world.

The at-berth rule catches the auxiliary-engine & boiler load a ship burns while alongside, which on a long port call is far from negligible. The 50% extra-EEA share is the political compromise that lets the EU reach beyond its own waters without claiming the whole of a transoceanic voyage. A Singapore-Rotterdam laden leg counts at 50%; the Rotterdam-Hamburg feeder leg that follows counts at 100%. Attributing each voyage’s CO2 to the right bucket before you aggregate is exactly what the EU ETS Scope Factor calculator is for, and the underlying weighting is summarized here:

There’s a recognized weakness in the 50% design, and it drives behavior. A non-EEA transhipment port located just outside the 50% boundary can convert what would have been a single inbound voyage into two legs, one of them entirely outside the system. That evasion incentive is real enough that the directive named specific neighboring container ports for monitoring and built in anti-evasion review provisions. More on that in the limitations section below.

The phase-in of the surrender obligation

Shipping doesn’t pay 100% from day one. The directive ramps the surrender obligation over three years, under the Article 3gb phase-in and the Article 3ga scope rules , so the market and operators can adjust. The percentage applies to the covered emissions of a given reporting year, and the allowances are surrendered the following September.

Read it through the calendar and it means: for 2024 emissions you surrendered 40% of the covered tonnage by September 2025; for 2025 emissions you surrender 70% by September 2026; from the 2026 reporting year (surrendered September 2027) the full 100% applies and stays there. A ship that emitted 10,000 tonnes of covered CO2 in 2024 had to surrender 4,000 EUAs. The same ship & the same emissions in 2026 would owe 10,000 EUAs. The phase-in factor is doing real work on the bill in the first two years, which is why the EU ETS Phase-in Schedule calculator bakes the year-to-factor mapping in automatically rather than leaving it as a hand step.

The phase-in is a discount on quantity, not a discount on price. You still buy the allowances at the market rate for whatever fraction applies. A common planning error is to treat the 40% & 70% years as a grace period and under-budget for the cash impact of the jump to 100%, which is 2.5 times the 2024 liability for an unchanged ship sailing an unchanged pattern.

A concrete case shows the arithmetic. Take a Suezmax tanker that burns 30,000 tonnes of VLSFO in a year, all on voyages that attribute fully or partly to the EEA, and assume that after the 100/50/0 weighting strips out the non-EEA share its covered CO2 works out to 60,000 tonnes. In the 2024 reporting year at 40%, the surrender is 24,000 EUAs. In 2025 at 70% it’s 42,000 EUAs. From 2026 at 100% it’s 60,000 EUAs. At an EUA price of EUR 80, that’s EUR 1.92 million, EUR 3.36 million, & EUR 4.8 million across the three years for the same ship doing the same work, on CO2 alone and before any CH4 or N2O from the 2026 gas expansion is added. The jump comes from the phase-in factor while the ship’s operation stays flat. That’s the number a charter negotiation, a budget, & a fuel-switch business case all have to start from.

The gases covered, and the 2026 expansion

For 2024 and 2025, the maritime ETS covers carbon dioxide only. From the 2026 reporting year, methane (CH4) and nitrous oxide (N2O) are added. That’s not a footnote for ships burning gas. Methane has a far higher global-warming potential than CO2 per unit mass, and low-pressure dual-fuel engines running on LNG release unburnt methane through the exhaust, the phenomenon known as methane slip. A vessel that looked attractive on a CO2-only basis because LNG’s carbon factor is lower than fuel oil’s can find its 2026 liability bumped up once slipped methane is priced as CO2-equivalent.

The CO2-equivalent conversion uses global-warming-potential factors so a tonne of methane translates into many tonnes of allowance liability. The practical effect: from 2026, the ETS stops rewarding a fuel switch that merely moves the emission from the stack as CO2 to the stack as methane. The interplay between LNG’s lower carbon factor and its methane penalty is one of the reasons the choice of LNG as a marine fuel is more finely balanced under the full ETS than under a CO2-only regime.

N2O is the smaller of the two additions in mass terms but it isn’t zero. It comes mainly from combustion in conventional engines & from certain after-treatment chemistry, and like methane it carries a high GWP per tonne. Adding both gases from the 2026 reporting year aligns the ETS coverage with the way the IMO & the wider climate accounting treat shipping’s footprint, which is on a CO2-equivalent basis rather than CO2 alone. For an operator, the change means the 2026 monitoring plan has to capture more than fuel-derived CO2: the verifier needs a basis to quantify CH4 & N2O, and the MRV implementing rules set out how those are to be determined. A monitoring plan written for a CO2-only world in 2024 has to be revised before the 2026 year starts, not after.

There’s a timing subtlety in the gas expansion worth flagging. The 100% surrender share and the CH4/N2O coverage both bite on the 2026 reporting year, so the step from the 2025 bill to the 2026 bill stacks three effects at once: the quantity rises from 70% to 100% of CO2, the gas basket widens from one gas to three, and the EUA price does whatever the market does. An operator that models 2026 as simply “2025 grossed up to 100% of CO2” will understate the liability by leaving out the new gases entirely.

The MRV regulation as the data backbone

The ETS doesn’t invent a new way to measure ship emissions. It reuses the monitoring infrastructure that’s been running since 2018 under the EU MRV Regulation, Regulation (EU) 2015/757. MRV already required ships above 5,000 GT calling at EEA ports to monitor fuel consumption per voyage, calculate CO2 using fuel-specific carbon factors, have the result verified by an accredited verifier, and submit an annual emissions report. Regulation (EU) 2023/957 amended MRV so its output plugs straight into the ETS: it added the voyage-level geographic attribution, the company-level aggregation the ETS needs, and the at-berth & gas-coverage hooks.

The compliance cycle hangs off the MRV calendar. The monitoring plan has to be assessed by the verifier, emissions are monitored per voyage through the year, and under Article 11(1) of Regulation (EU) 2015/757 as amended by Regulation (EU) 2023/957 the verified ship-level emissions report and the company-level aggregated emissions data (the figure the surrender obligation is calculated from) are both due by 31 March. The administering authority may require them earlier, but not before 28 February. The fuel-to-CO2 conversion uses the carbon factors set out in the MRV implementing rules, the same factors family used across IMO measures. Because the data already feeds carbon intensity reporting and overlaps with the IMO Data Collection System , most operators are not building a new data pipeline, they’re extending one. The EU MRV Annual Report Scope calculator and the EU MRV to EU ETS Allowance Crosswalk sit on either side of that handoff: one shapes the report, the other turns it into an allowance number.

A practical note on verification: the verifier that signs the MRV report is the gatekeeper for the whole ETS chain. An unverified or qualified emissions report can’t be turned into a clean surrender, so the verifier relationship & the monitoring-plan quality matter more under ETS than they did when MRV was a reporting-only exercise.

Who is the responsible entity

The obligation lands on the “shipping company,” and the directive is specific about who that is. It’s the shipowner, or any other organization or person such as the manager or the bareboat charterer that has assumed responsibility for the operation of the ship from the owner. In practice, for most managed ships that’s the ISM company: the entity named on the Document of Compliance under the International Safety Management Code, the same organization responsible for the safety-management system. The ISM link is deliberate. It points the obligation at whoever actually controls how the ship is operated & how much fuel it burns, not at a paper owner.

That assignment can move. Where responsibility for operation transfers during a year, Article 11(2) of the MRV Regulation, as amended by Regulation (EU) 2023/957, provides for the obligation to follow the responsible entity. The company has to be registered & identified to its administering authority, and a clear, documented chain of who held operational responsibility for each voyage becomes part of the compliance record. Getting this wrong, for example a manager assuming a charterer carries the obligation when the directive places it on the ISM company, is one of the more expensive misreadings of the regime.

The polluter-pays pass-through, and the charter-party problem

The directive recognizes that the company holding the ETS obligation is often not the party that decides the ship’s speed, route, or fuel: in a time charter, the charterer gives the orders and pays for the bunkers. Article 3gc of the amended directive entitles the shipping company to claim reimbursement from the entity that’s directly responsible for the decisions affecting the ship’s CO2 emissions, the “polluter pays” pass-through. The directive sets the principle. It leaves the contractual mechanism to the parties.

That’s where the charter party comes in. BIMCO published the ETS - Emission Trading Scheme Allowances Clause for Time Charter Parties 2022 so owners & charterers have standard wording to allocate the cost. Under it the charterers “provide and pay for the Emission Allowances corresponding to the Vessel’s emissions” throughout the charter period. The owners notify the quantity for the previous month within the first seven days of each month, and the charterers transfer those allowances into the owners’ nominated account within seven days of notification. For the final month, the owners notify an estimate no later than 14 days before expected redelivery, and the estimate is trued up against the actual quantity, in allowances, after redelivery. Allowances for off-hire periods can be offset or returned. If the charterers fail to transfer, the owners may suspend performance on five days’ notice while the vessel remains on hire. The clause settles in allowances only; it has no cash alternative. BIMCO’s separate Emission Scheme Surcharge Clause, published in 2023, is a voyage charter clause. Without an agreed clause, an owner who holds the ETS obligation while the charterer controls the fuel and the orders can be left carrying a cost the directive says belongs to the charterer, with reimbursement to be argued after the fact. The allocation isn’t settled by the regulation; it’s settled by the contract. The EU ETS Annual Allowance Cost card below is useful at the negotiation stage because it puts a defensible euro figure on the allowances each side is arguing over.

The compliance workflow, step by step

The administrative spine of the ETS is the registry. Allowances are electronic instruments held in accounts in the Union Registry. The maritime side runs through what the Commission calls the Maritime Operator Holding Account (MOHA), opened with the company’s administering authority. The administering authority for a company is fixed by Article 3gf(1) of the amended directive: the member state where the company is registered; for a company not registered in a member state, the member state with the greatest estimated number of port calls from its in-scope voyages in the preceding four monitoring years; and for a company with no in-scope voyage in those four years, the member state where a ship of the company started or ended its first in-scope voyage. Commission Implementing Regulation (EU) 2023/2599 sets the data behind that attribution (the country of registration recorded in THETIS-MRV, port calls from SafeSeaNet) and requires a manager or bareboat charterer taking on the ETS obligations to be duly mandated by the shipowner in a document signed by both. Once assigned, that authority is your single regulatory counterpart for ETS.

The annual cycle runs like this. Monitor emissions per voyage through the reporting year under the approved monitoring plan. Submit the verified ship-level emissions report and the company-aggregated emissions data, both by 31 March of the following year. The administering authority confirms the allowance obligation. Surrender the required EUAs from the MOHA by 30 September. Allowances are fungible market instruments: a company can buy them at auction, on the secondary market, or hold them across years, then move them into the surrender. The EU ETS Allowance Surrender Schedule calculator helps a company that’s running several ships work out the pooled surrender quantity & timing across the fleet rather than ship by ship.

The cash-flow shape matters. Emissions accrue continuously through the year, but the allowances aren’t surrendered until the following September, up to 21 months after the earliest emissions of a reporting year. A company can buy allowances steadily as it emits, smoothing the cost, or wait & buy in bulk before the deadline, taking price risk. Either way the surrender is a single large outflow against a market price the company doesn’t control.

Opening the MOHA is the first practical step, and it isn’t instant. The account-opening process with the administering authority requires identity & authorization documents, a named account representative, & the usual anti-money-laundering checks that apply to any Union Registry account. A company that leaves account-opening until close to its first surrender deadline can find itself unable to transfer allowances in time, which is a self-inflicted route into the EUR 100 penalty. The directive’s design assumes a company is registered, identified, & holding an active account well before its first 30 September.

Sourcing the allowances is a separate decision from holding them. EUAs come to market through primary auctions, run on a common auction platform, & through the secondary market where they trade like any commodity, including futures that let a company lock a forward price. A shipping company doesn’t have to buy at auction; most will buy in the secondary market or take allowances a trading desk has already acquired. The choice between buying steadily through the year & buying near the deadline is a treasury call about price risk, not a compliance requirement. What the regulation fixes is only the quantity owed & the surrender date, not how or when the company acquires the instruments to meet it.

Penalties for non-surrender

Missing the surrender deadline is expensive, and the penalty doesn’t discharge the underlying obligation. The excess emissions penalty under the ETS Directive is EUR 100 for each tonne of CO2 equivalent emitted for which allowances were not surrendered by the deadline (Article 16(3), applied to shipping companies by Article 16(3a)), and that figure is index-linked to European consumer prices, so the real number rises over time. Crucially, paying the penalty does not release the company from surrendering the missing allowances: you pay EUR 100 per tonne and still have to hand over the allowance. The names of operators that fail to comply are also published, a reputational cost on top of the financial one.

The maritime regime adds a sanction the rest of the ETS doesn’t have. If a shipping company has failed to comply with the surrender obligation for two or more consecutive reporting periods, and other enforcement measures have failed, Article 16(11a) lets the competent authority of the member state of the port of entry issue an expulsion order after giving the company the opportunity to submit its observations. Every member state other than the flag state then refuses entry to the ships under that company’s responsibility until it fulfils its surrender obligations, and the member state whose flag the ship flies shall detain the ship; the flag member state may also issue a flag State detention order, after which every member state takes the same measures. For a commercial operator, losing access to EU ports is an existential sanction, far heavier than the per-tonne penalty. The escalation from a price-based penalty to a market-access ban is the directive’s answer to any operator tempted to treat the EUR 100 charge as a cost of doing business.

The expulsion order travels with the company, not the individual ship, which is the point that catches owners by surprise. A clean ship under a non-compliant company’s operational responsibility can be refused port entry because the company, not the hull, is the regulated entity. The order is issued by the member state of the port of entry and notified to the Commission, EMSA, the other member states and the flag state, and every other member state then refuses entry, so a ban isn’t escaped by routing to a different member state’s ports. That cross-border effect is what gives the sanction teeth: there’s no friendly port to retreat to inside the system. The directive keeps one exception, stating that the order applies “without prejudice to international maritime rules applicable in the case of ships in distress”. The order can be lifted once the company brings itself back into compliance, but until then every covered ship it operates is exposed.

The verification dependency is a quieter failure mode than a missed deadline. Because the surrender quantity is built on the verified MRV emissions report, a report that the verifier qualifies or refuses to sign can’t produce a clean obligation figure, & the company can find itself in default through a data dispute rather than a deliberate non-payment. Administering authorities can estimate emissions where a report is missing, & that estimate is rarely in the company’s favor. Keeping the monitoring plan, the verifier relationship, & the underlying fuel data in order through the year is the cheapest insurance against the penalty regime.

What revenue does, and the Ocean Fund question

Auctioning allowances raises money, and the directive directs where it goes. Under Article 10(3) as amended, member states use their auction revenues, except those used to compensate indirect carbon costs under Article 10a(6), for climate purposes, and a defined volume of allowances feeds the Innovation Fund, the EU instrument that supports first-of-a-kind low-carbon technology. Directive (EU) 2023/959 sets no maritime allowance earmark inside the fund. Article 10a(8) instead requires the Commission to “give special attention to projects contributing to the decarbonisation of the maritime sector” and to include topics dedicated to that purpose in Innovation Fund calls, and it makes maritime projects with clear added value for the Union eligible.

There is no separate ring-fenced maritime “Ocean Fund” in the final text, despite a long campaign for one during the legislative process. The European Parliament had pushed for an Ocean Fund that would have recycled a large share of maritime ETS revenue directly back into the sector’s decarbonization & into vulnerable port communities. The compromise that passed routes maritime support through dedicated topics in the existing Innovation Fund’s calls rather than a standalone fund. The distinction matters to operators because it shapes how much of the carbon they pay for is available to subsidize the fuels & retrofits that would cut that carbon: shipping competes for a share of a general fund, with no full recycling of the sector’s contribution.

For an operator weighing a retrofit or an alternative-fuel newbuild, the Innovation Fund is a partial offset, not a guaranteed subsidy. The fund runs competitive calls; a project has to win against other applicants on cost per tonne of CO2 avoided & on maturity. So the right way to read the revenue-use rules is that the ETS makes carbon expensive every year for every covered ship, while the support side reaches only the subset of projects that win funding. The asymmetry is deliberate: the price signal is universal & the subsidy is selective, which is how a cap-and-trade system is meant to push abatement toward the cheapest options rather than spread thin support across everyone.

There’s also a member-state layer to the revenue. Auction proceeds flow to national budgets, & Article 10(3) requires member states to use those revenues, other than indirect cost compensation, for climate-related purposes, but the directive doesn’t force a state to hand the money back to the shipping companies that paid it. A company can pay millions in EUAs into a market whose auction revenue lands in a national treasury & funds, for example, a domestic renewables program rather than a port shore-power installation. That’s not a defect; it’s how the broader ETS has always worked. For shipping it means the sector’s carbon payments & the sector’s decarbonization support are loosely coupled, connected through the Innovation Fund’s maritime call topics rather than a direct pipe.

Interaction with FuelEU Maritime and the IMO framework

The ETS is one of three carbon regimes a ship can sit under at once, and they don’t measure the same thing. FuelEU Maritime , in force from 1 January 2025 under Regulation (EU) 2023/1805, sets a declining limit on the greenhouse-gas intensity of the energy a ship uses on EEA-related voyages, measured well-to-wake. The ETS prices the absolute tonnage of CO2 (and from 2026 CH4 & N2O) the ship emits, measured tank-to-wake. So a sustainable fuel that scores well under FuelEU’s well-to-wake metric & a fuel that has a low tank-to-wake carbon factor under ETS are not always the same fuel, and the two regimes can pull a fuel decision in different directions. A renewable fuel of non-biological origin can earn strong FuelEU credit while a biofuel’s tailpipe carbon is treated as zero under ETS: the optimization isn’t single-variable.

The third regime is the IMO’s global framework. The IMO net-zero framework approved at MEPC 83 in April 2025, formal adoption of which is still pending after the October 2025 extraordinary session adjourned without a decision, would pair a global fuel-intensity standard with an emissions-pricing mechanism designed to apply worldwide rather than to EEA-touching voyages. The EU has said it will review the relationship between its measures & the IMO’s once the global mechanism is operational, to avoid double-charging the same tonne, but that reconciliation isn’t settled. For now, a ship trading into Europe can face ETS allowances, a FuelEU intensity balance, and IMO obligations against overlapping but differently-defined emissions. The reduction levers underneath are mostly shared, though. Burning less fuel through slow steaming , hull cleaning, & better routing cuts the ETS bill, helps the carbon intensity indicator rating, and lowers FuelEU exposure at the same time. The carbon factor of the fuel sits at the center of all of them, which is why the MARPOL Annex VI fuel-and-emissions framework is the common reference. For the secondary trading & price-formation side, the EUA market mechanics for shipping article covers how allowances are bought, banked, & priced, and the parallel UK ETS for shipping regime shows how a post-Brexit carbon market diverges from the EU one.

Limitations

The 50% extra-EEA design creates an evasion incentive that the directive itself acknowledges. A non-EEA transhipment hub positioned just outside the boundary can split an inbound voyage so that the long leg, the one that would have been charged at 50%, becomes a non-EEA-to-non-EEA leg charged at 0%, with only the short feeder leg into Europe carrying the full charge. The directive named neighboring container ports for monitoring and built in a review of evasion, but the commercial pull toward transhipment hubs outside the system is structural, not a loophole that a single rule closes. Carbon leakage of cargo flows, not just emissions, is the harder version of the same problem.

Who actually pays is unsettled in practice even though the directive is clear in principle. The obligation sits on the shipping company, the reimbursement right points at the charterer, and the contract is supposed to bridge the two. On a spot voyage charter, a time charter with an old clause, or a chain of sub-charters, the pass-through can break down, and the company holding the MOHA can be left financing allowances it expects to recover later. The BIMCO clause helps where it’s incorporated, but the market hasn’t fully standardized, and disputes over attribution of voyages to charterers are a live risk.

EUA price volatility makes the liability a moving target. With allowances ranging across tens of euros per tonne within a single year, a fleet’s annual carbon cost can swing by a large fraction on price alone, independent of any operational change. The phase-in masks this in the early years, then the step to 100% in the 2026 reporting year compounds a quantity increase with whatever the price does. Budgeting & hedging the carbon cost is now a treasury function, not just an environmental one, and the surrender-timing gap of up to 21 months between emission & payment is a cash-flow burden that smaller operators feel more acutely than the majors.

The regime’s reach also stops at coverage definitions that don’t match the physics of a voyage. The 5,000 GT threshold leaves a fleet of smaller ships outside the surrender obligation for now, the at-berth rule depends on accurate apportionment of auxiliary load, and the GWP factors used to price methane from 2026 are a policy choice that can change as the science & the IMO position evolve. Finally, the interaction with FuelEU & the IMO framework is not yet reconciled, so a ship can be charged under more than one regime for overlapping emissions until the EU completes the review it has promised. None of these is a reason the regime fails to bite. They’re the edges a practitioner has to plan around rather than assume away.

Related Articles

• FuelEU Maritime explained
• EUA Market Mechanics for Shipping
• UK ETS for Shipping
• IMO net-zero framework
• What is CII? Carbon Intensity Indicator explained
• MARPOL Annex VI
• LNG as a marine fuel
• Slow steaming