FuelEU penalties, pooling & the RFNBO multiplier

FuelEU Maritime stopped being a reporting exercise on 1 January 2025. Regulation (EU) 2023/1805 now puts a price on the well-to-wake greenhouse-gas intensity of the energy a ship burns on EU voyages, and the price is steep: EUR 2,400 for every tonne of VLSFO-equivalent energy the ship runs short of its yearly target. The headline number is easy to quote. The mechanics underneath it (the compliance balance, the consecutive-year escalation, banking, borrowing, pooling across a fleet, and the RFNBO double-count) decide whether an operator pays that figure or routes around almost all of it. This article is the quantitative deep-dive for the penalty side of the regime. For the scope, the intensity target curve, and the monitoring plan, start with the parent overview at FuelEU Maritime explained.

The compliance balance: surplus or deficit, measured in CO2e

Everything starts with one number per ship per year. The compliance balance is the energy-weighted gap between the target GHG intensity and the intensity the ship actually attained, expressed in grams of CO2-equivalent. A positive balance is a surplus; you beat the target. A negative balance is a deficit; you missed it, and a deficit is what triggers the penalty.

The target for 2025 is 89.34 gCO2e/MJ, which is 2% below the 2020 fleet baseline of 91.16 gCO2e/MJ. The cut deepens on a five-year ratchet: 6% from 2030, 14.5% from 2035, 31% from 2040, 62% from 2045, and 80% from 2050. So a balance that’s comfortably positive in 2026 can flip negative in 2030 on the same fuel, because the target moved, not the ship. That timing is the whole reason banking exists, & it’s why operators model the balance out to 2035 rather than year by year.

The sign convention matters because it carries through every later step. Write the per-ship balance as $CB = (GHG_{target} - GHG_{actual}) \times E$, where $E$ is the total energy in megajoules used in scope. A ship attaining 91.7 gCO2e/MJ against an 89.34 target has a negative bracket of $-2.36$ gCO2e/MJ. Multiply by the year’s energy and you get the deficit in grams, which the regulation then converts to tonnes for the penalty. Surplus and deficit are the same arithmetic with the sign flipped, and that symmetry is what makes pooling possible: one ship’s positive grams cancel another ship’s negative grams, one-for-one.

The energy term $E$ isn’t the full bunker figure. FuelEU counts 100% of energy on intra-EU voyages and at EU berths, but only 50% of energy on voyages into or out of the EU. The same 50/50 split governs EU ETS for shipping, so the in-scope energy you compute for one regime feeds straight into the other. Get the scope split wrong and both your FuelEU balance & your EUA surrender obligation are wrong by the same proportion.

The intensity that goes into $GHG_{actual}$ is well-to-wake, not tank-to-wake. That distinction is what separates FuelEU from the IMO’s Carbon Intensity Indicator & from EU ETS, both of which work on tank-to-wake CO2 only. Well-to-wake adds the upstream emissions of producing & delivering the fuel to the combustion emissions, & it counts methane (CH4) & nitrous oxide (N2O) alongside CO2 on a 100-year global-warming-potential basis. The practical effect is that an LNG ship can’t claim the full tank-to-wake carbon saving of methane, because methane slip from the engine & upstream leakage in the gas supply chain both load the well-to-wake number. A dual-fuel ship that looks clean on a CII basis can post a FuelEU intensity that’s only marginally better than VLSFO once slip is counted, & that gap is exactly what the balance captures.

The default intensity values come from the regulation’s own tables in Annex II, which assign a well-to-wake figure to each fuel pathway, plus engine-specific slip factors for the gas engines. An operator can use a verified actual value instead of the default where it has certified data, & for RFNBOs the certified pathway value is what unlocks both the low intensity & the multiplier. The choice between default & actual values is itself a compliance lever: a low-pressure dual-fuel engine carries a higher default slip factor than a high-pressure one, so an operator with measured slip data below the default can improve its balance by documenting the real number rather than accepting the table.

The FuelEU penalty: Annex IV, EUR 2,400 per VLSFO-equivalent tonne

When the balance is negative, Article 23 read with Annex IV sets the bill. The deficit in grams is converted to VLSFO-equivalent tonnes by dividing by the attained intensity and by 41,000 (the lower calorific value of VLSFO, 41 MJ/kg expressed in MJ per tonne). Each such tonne costs EUR 2,400.

The 41,000 figure isn’t arbitrary. The regulation needed a common unit to compare a methane-slip deficit on an LNG ship against a sulfur-free deficit on a VLSFO ship, so it normalizes everything to the energy content of one tonne of VLSFO. The denominator in Annex IV is $GHG_{actual} \times 41{,}000$, which turns a grams-of-CO2e deficit into tonnes-of-fuel-equivalent. The penalty then prices that fuel-equivalent at EUR 2,400/t, roughly double what a tonne of conventional fuel cost at the time the regulation was drafted, so non-compliance is engineered to be more expensive than buying compliant fuel.

Work a real case. Take a 200,000-tonne-per-year operator burning only VLSFO at a well-to-wake intensity of 91.7 gCO2e/MJ in 2025:

• Excess intensity over the target: $91.7 - 89.34 = 2.36$ gCO2e/MJ.
• In-scope energy, assuming all energy counts: $200{,}000 \text{ t} \times 41{,}000 \text{ MJ/t} = 8.2 \times 10^9$ MJ.
• Compliance deficit in grams: $2.36 \times 8.2 \times 10^9 = 1.935 \times 10^{10}$ gCO2e, i.e. 19,350 tonnes CO2e.
• VLSFO-equivalent tonnes: $\frac{1.935 \times 10^{10}}{91.7 \times 41{,}000} \approx 5{,}150$ t.
• Penalty: $5{,}150 \times 2{,}400 \approx$ EUR 12.4 million.

That’s one ship-year, on a fuel that meets MARPOL Annex VI sulfur limits perfectly. FuelEU isn’t a sulfur rule; it’s a carbon-intensity rule, and conventional fossil fuel fails it from day one. Compute your own mix’s attained intensity in the FuelEU GHG intensity calculator and price the gap in the FuelEU penalty calculator to see how fast the number moves with a few percent of biofuel or RFNBO blended in. The same operator dropping attained intensity to 88.5 gCO2e/MJ (below target) pays nothing & banks a surplus instead.

The penalty is paid annually to the administering authority, ring-fenced under Article 21 for projects that support maritime decarbonisation. Paying it does not extinguish the obligation in a way that resets the clock, which is the trap the next section covers.

The EUR 2,400 prices something specific. It is not a carbon price in the EU ETS sense, where the unit is one tonne of CO2 & the price floats on an auction market. The FuelEU unit is one tonne of VLSFO-equivalent energy short of target, & the rate is fixed in the regulation, not set by a market. So the two regimes price different things: ETS prices the carbon emitted, FuelEU prices the energy that should have been cleaner. A ship can owe both for the same voyage, on the same fuel, computed two different ways, & the double regulation of EU ETS & FuelEU is the reason a single fuel-switch decision has to be modelled against both bills at once. The interaction isn’t additive in a simple way: an RFNBO that zeroes the ETS carbon factor also zeroes the FuelEU intensity & earns the x2 multiplier, so the marginal value of the same e-fuel tonne is the sum of an avoided EUA, an avoided FuelEU penalty, & a doubled surplus, which is why the per-tonne value of RFNBO often runs three to four times its commodity premium over fossil MGO.

The conversion through the attained intensity in the denominator has a second-order effect operators miss. Because the deficit-to-tonnes step divides by $GHG_{actual}$, a dirtier ship converts the same grams-deficit into slightly fewer VLSFO-equivalent tonnes than a cleaner ship would, since the larger denominator shrinks the quotient. The effect is small at the margin, but it means two ships with the same gram-deficit but different attained intensities don’t pay exactly the same penalty. The Annex IV formula is internally consistent on this point: the conversion is anchored to the ship’s own intensity precisely so the VLSFO-equivalent tonnage reflects how much compliant energy the ship would have needed to close the gap.

The 1.1 escalation: each consecutive deficit year costs 10% more

Article 23 doesn’t let a ship pay the same EUR 2,400 forever. For each consecutive year a ship records a deficit, the penalty is multiplied by an escalation factor that grows 10% per year. The factor is $1 + 0.10 \times (n - 1)$, where $n$ is the number of consecutive non-compliant years. Year one: factor 1.0. Year two: 1.1. Year three: 1.2. The surcharge is capped at five times the base rate, so the multiplier tops out at 5.0.

Run the 200,000-tonne operator forward, assuming the fuel mix doesn’t change and the target tightens on schedule:

• 2025 (year 1): EUR 12.4 million at factor 1.0.
• 2026 (year 2): same deficit, factor 1.1, so roughly EUR 13.6 million.
• 2027 (year 3): factor 1.2, roughly EUR 14.9 million.
• And the underlying deficit itself grows as the target ratchets toward the 2030 step.

The escalation is the regulation’s anti-procrastination device. An operator who treats the penalty as a fixed compliance cost discovers it’s a rising one, & a deficit that runs from 2025 to 2030 stacks the 1.1 factor five times against a target that has also moved 4 percentage points. That compounding is what practitioners mean by the FuelEU debt spiral: the cheapest year to fix a deficit is always the first one. The escalation resets only when the ship posts a compliant year, so a single surplus year (whether earned, banked-in, or pooled-in) breaks the chain & sends $n$ back to 1.

The reset rule changes the economics of every other lever. If pooling-in enough surplus to flip one ship to compliant for a single year costs less than the escalation it would otherwise pay across the following years, the pool buy is worth it for the reset alone, separate from the penalty it avoids that year. The same logic applies to a one-off RFNBO bunkering: a single year of e-fuel that pushes the balance positive doesn’t just clear the current deficit, it sends the multiplier back to 1.0, so the avoided cost includes the difference between paying factor 1.0 next year & paying factor 1.3 or 1.4 had the chain continued. Practitioners price the reset as a distinct line in the trade-off, not a side benefit.

The cap at five times the base rate is a ceiling on the multiplier, not on the bill. A ship that reaches $n = 5$ pays the maximum 5.0 factor, & then every subsequent deficit year stays at 5.0 while the underlying deficit itself keeps growing as the target steps down. So the worst-case operator (continuous deficit from 2025) sees the multiplier climb for the first five years & then sees the absolute penalty keep rising on the deficit term alone. There is no point at which a structural deficit becomes cheap to carry; the regulation is built so that the longer a ship waits, the larger the gap it has to close, because both the multiplier & the target are working against it.

Banking a surplus: carry it forward without a deadline

A ship that overshoots its target keeps the surplus. Article 6 lets a positive compliance balance be banked and applied to the same ship in a later reporting period, with no expiry. Beat the 2025 target by a wide margin & the surplus sits on the ship’s record until the operator chooses to spend it, which in practice means saving it for 2030 or 2035 when the target step makes compliance harder.

Banking rewards early action. A methanol-capable ship that runs e-methanol in 2026 when the target is loose generates more surplus per tonne than the same fuel would generate in 2031 against a tighter target, because surplus is measured against the year’s target, not an absolute. So the grams banked in a loose year are worth more later, when each gram is harder to earn. The banked balance attaches to the specific ship, not the company, which is the difference between banking & pooling: banking moves a balance through time on one hull, pooling moves it across hulls in one year.

There’s no cap on how much surplus a ship can bank, & no limit on how many years it can hold it. The only constraint is that the surplus must have been verified for the year it was generated. A balance the verifier didn’t confirm doesn’t exist for banking purposes, which is why the FuelEU Document of Compliance for the surplus year is the asset, not the operator’s own spreadsheet.

Banking & pooling can be combined in sequence, but not simultaneously on the same grams. A surplus generated in 2026 can be banked to 2027 & then, in 2027, pooled out to a sister ship, but the same grams can’t be both banked forward & pooled in the same year. The regulation tracks the balance as a single quantity per ship per period, so each unit of surplus is spent once: held, transferred, or applied. Operators who run both mechanisms keep a ledger of where each year’s surplus went, because double-counting a banked balance that’s already been pooled is the kind of error the verifier catches & that unwinds a pool’s compliance after the fact.

Borrowing an advance: up to 2%, once, with a 1.1 cost

The mirror of banking is borrowing, & it’s far more constrained. Article 7 lets a ship borrow an advance compliance surplus from the following reporting period to cover the current year’s deficit, but the borrowed amount can’t exceed 2% of the ship’s target multiplied by its in-scope energy. The borrowed grams are then deducted from next year’s balance, multiplied by 1.1, so borrowing carries a 10% surcharge on the borrowed quantity.

Two hard rules box it in. First, a ship can’t borrow in two consecutive periods; if you borrowed for 2025, you can’t borrow again for 2026. Second, the 2% ceiling means borrowing only covers a small miss. A ship that’s 2.36 gCO2e/MJ over target (a 2.6% gap against the 89.34 limit) is already past what borrowing can absorb, so borrowing is a tool for trimming a marginal deficit to zero, not for papering over a structural one.

The 1.1 borrowing surcharge is the same numerical factor as the consecutive-deficit escalation, but the two are unrelated mechanisms: one is a cost on advancing future surplus, the other is a penalty on repeated misses. The practical reading is that borrowing is cheap insurance against a small overshoot you expect to reverse next year, & expensive folly if next year’s surplus never materializes, because then you’ve created a deficit in year two as well & possibly triggered the escalation chain.

Pooling across ships: Article 21 and the verifier-confirmed pool

Pooling is the largest lever in the regime. Article 21 lets the compliance balances of two or more ships be combined into a single pool, so a surplus on one hull offsets a deficit on another in the same reporting period. The ships don’t have to share an owner; they have to share the pooling agreement & be verified by the same verifier or a coordinated set of verifiers. A liquefied-natural-gas ship running well under target, or a methanol-capable ship burning e-methanol, can carry a pool of conventional ships whose individual balances are negative.

The pool’s total balance is the sum of the member balances. If the pooled total is positive or zero, every ship in the pool is compliant for the year, regardless of its individual balance. The arithmetic is the same one-for-one cancellation as the compliance balance: surplus grams on the LNG ship erase deficit grams on the VLSFO ships until the pool nets out. Model a candidate pool before you commit to it with the FuelEU pooling calculator, which sums the member balances & flags whether the pool clears.

Article 21 builds in three protections. A ship can belong to only one pool per reporting period. The pooled compliance balance, after allocation, can’t leave any ship with a balance worse than it would have had outside the pool for the deficit ships, & the rule that no ship ends up worse off is enforced through the allocation step rather than left to the agreement. And the pool must be registered with the administering authority through the FuelEU database, with the allocation of the pooled balance to each ship recorded before the verifier confirms the Documents of Compliance. The verifier checks that the total balance is genuinely positive & that the allocation respects the no-worse-off rule before any ship in the pool is marked compliant.

The allocation method is where the commercial deal lives. The regulation fixes the no-worse-off floor but lets the members agree how the surplus is shared & priced. A surplus ship effectively sells its grams to the deficit ships, & a market has formed at roughly 60% to 80% of the avoided penalty: a deficit ship facing a EUR 10 million penalty pays the surplus ship somewhere between EUR 6 million & EUR 8 million for enough grams to clear, splitting the saving. The surplus ship monetizes an asset it earned by burning cleaner fuel; the deficit ship pays less than the penalty would have cost. Move a confirmed surplus between specific ships with the FuelEU pooling surplus transfer calculator when you’re allocating a known credit rather than testing a whole pool.

The economics scale with the surplus ship’s headroom. One methanol-capable retrofit running e-methanol can generate enough surplus to carry a pool of five to ten conventional ships for a few years, because the surplus grams from a single deep-cutting ship dwarf the per-ship deficits of fossil ships that are each only a few percent over target. That asymmetry is what makes early investment in one clean ship a fleet-wide compliance asset rather than a single-hull one. Some owners now run this as a service: a ship with surplus accepts third-party deficit ships into its pool for a fee, turning a compliance overshoot into a revenue stream. The price holds below the penalty because the deficit ship’s alternative is the full EUR 2,400 rate plus any escalation, so the surplus ship can charge up to that ceiling minus the deficit ship’s expected saving.

The timing constraints on pooling are tight. The pool must be formed & registered within the reporting & verification cycle for the year it covers, the allocation locked before the verifier confirms the Documents of Compliance, & no ship can be moved between pools after the fact. A ship that discovers a deficit late, after verification has begun, may find the surplus ships it needs are already committed to other pools, since each can join only one pool per period. So pooling is a planning decision made early in the year against forecast balances, not a year-end rescue, & operators who treat it as the latter find the surplus market thin & the deadlines closed.

The RFNBO reward multiplier: x2 energy through 2033

Renewable fuels of non-biological origin (RFNBOs) get a reward the regulation grants no other fuel. From 1 January 2025 to 31 December 2033, the energy from an RFNBO counts twice toward the compliance balance: 1 megajoule of RFNBO energy is treated as 2 megajoules in the energy-weighting. The multiplier sits in the denominator of the intensity calculation, so it both dilutes the fleet-average intensity & inflates the surplus that compliant RFNBO energy generates.

The effect is larger than it first looks. A ship that replaces 1% of its physical energy with a zero-intensity RFNBO doesn’t just shave 1% off its attained intensity; with the x2 multiplier the RFNBO energy is weighted as 2% of the denominator, so the attained intensity falls roughly twice as fast per physical tonne of e-fuel bought. That’s the regulation’s deliberate investment signal: the same e-methanol or e-ammonia that costs a premium over fossil MGO buys double the FuelEU benefit it would buy on energy content alone, & the window closes at the end of 2033.

The qualifying bar is strict. An RFNBO under FuelEU is an e-fuel made from non-biological renewable energy that meets the lifecycle GHG thresholds of the Renewable Energy Directive (RED II, Directive (EU) 2018/2001) & is certified under a recognized voluntary scheme. E-methanol from electrolytic hydrogen plus captured CO2, e-ammonia from green hydrogen, & e-LNG qualify; bio-methanol, HVO, & used-cooking-oil FAME do not, because they’re biofuels, not RFNBOs. Biofuels get favourable treatment under FuelEU through their low certified intensity, but they don’t get the x2 multiplier. The eligibility test is exacting enough that operators run it separately before counting the bonus; the rules sit at RFNBO under EU fuel law.

The certification chain is where claims fail. An RFNBO’s well-to-wake intensity & its non-biological-renewable origin both have to be documented through a proof-of-sustainability certificate that follows the fuel from the production plant to the ship’s tank. A break anywhere in that chain (an uncertified intermediate, a mass-balance gap at a terminal, a certificate that doesn’t match the delivered batch) & the fuel reverts to its default fossil-equivalent intensity for FuelEU purposes, losing both the low intensity & the x2 weighting. The bunker delivery note & the certificate have to agree on quantity & pathway, so an operator buying e-methanol for the multiplier needs the certification in hand before the balance is computed, not after. The physical molecule being clean isn’t enough; the paper trail is what the verifier counts.

The multiplier also interacts with the choice of clean fuel. E-ammonia carries no carbon in the molecule, so its tank-to-wake CO2 is zero, but the well-to-wake number still depends on whether the hydrogen feedstock was made with additional renewable electricity. E-LNG qualifies as an RFNBO only if the methane is synthetic & renewable, & it still carries the engine methane-slip penalty that loads its well-to-wake intensity, so e-LNG’s net FuelEU benefit is smaller per energy unit than e-methanol or e-ammonia despite all three earning the x2 weighting. The multiplier doubles whatever surplus the fuel generates; it doesn’t equalize the fuels, so the fuel-selection case still turns on the certified intensity of each pathway.

The sub-target and the double-count interaction

The multiplier doesn’t stand alone. Article 5 sets a 2% RFNBO sub-target that activates from 2034 if the Commission finds RFNBO uptake below 1% of fuel mix in 2031, & ships that miss the sub-target face a separate penalty. The x2 multiplier through 2033 is the carrot that’s meant to pull uptake above that 1% trigger so the sub-target never bites.

This is where the double-count gets subtle. The same physical RFNBO energy is weighted x2 for the main GHG-intensity balance through 2033, & separately the regulation prevents the same megajoule from being claimed twice across the main balance & the sub-target accounting. Operators planning RFNBO purchases for both the intensity reward & a future sub-target position need to track which megajoules are counted where, because the certificate of sustainability is consumed once. The FuelEU RFNBO double-count calculator isolates the multiplier effect on the balance from the sub-target contribution so the two aren’t conflated.

The Document of Compliance and the two-year expulsion risk

The monetary penalty isn’t the worst outcome. Each ship receives a FuelEU Document of Compliance from its verifier when it’s compliant for a year, whether through its own fuel, banked surplus, borrowing, or pooling. The Document is the proof a ship presents to port authorities. A ship that fails to hold a valid Document of Compliance for two or more consecutive reporting periods can be issued an expulsion order: a Member State can refuse it entry to all EU ports until the Document is reinstated, & a ship flying a Member State flag can be detained.

That consequence reorders the whole compliance calculus. A EUR 12 million penalty is a number on a P&L; losing EU port access is a vessel that can’t trade its main market. The two-consecutive-year trigger is also why the escalation chain & the Document risk run on parallel clocks: a ship that pays the penalty but never posts a compliant year is both watching its bill climb 10% annually & walking toward the expulsion threshold. The operator who treats year one as the cheap fix is reading the regulation correctly. For how the responsible company is defined & how the obligation moves between owner & operator, the parent article at FuelEU Maritime explained sets out the company-of-record rules.

Picking the lever: bank, pool, or pay

The four flexibility mechanisms aren’t interchangeable, & the cheapest path depends on the size & shape of the deficit. A marginal miss under 2% of target-times-energy is a borrowing case, if next year’s surplus is genuine: it costs the 1.1 surcharge & nothing else. A structural deficit on a single fossil ship within a mixed fleet is a pooling case: route a sister ship’s surplus to it & pay the internal transfer price, which clears at 60% to 80% of the penalty. A surplus generated in a loose year is a banking case: hold it for the 2030 step rather than spending it against an easy 2026 target.

Paying the penalty is the residual, the option that prices every other one. Pooling only makes sense below the penalty; banking only makes sense if the future target makes the surplus more valuable held than spent; borrowing only makes sense if it’s cheaper than the escalation it avoids. The arithmetic that ties them together is the compliance balance, so the planning sequence is always the same: compute each ship’s balance, identify the deficits, then test pool-versus-bank-versus-borrow-versus-pay against the EUR 2,400 rate & the 1.1 escalation.

A worked decision shows the ranking. Take the 200,000-tonne fossil ship from earlier, sitting on a EUR 12.4 million 2025 deficit, inside a fleet that also has a methanol ship running a EUR 9 million surplus. Borrowing is out: the deficit is 2.6% of target-times-energy, above the 2% cap, so borrowing can’t clear it. Banking is irrelevant; this ship has no surplus to bank, & the methanol ship’s surplus is better deployed than parked. Pooling clears it: route enough of the methanol ship’s grams to flip the fossil ship positive, pay an internal transfer at 70% of the avoided penalty (about EUR 8.7 million), & both ships hold a Document of Compliance. The residual surplus on the methanol ship is then banked for the 2030 step. The fossil ship paid EUR 8.7 million instead of EUR 12.4 million, kept its multiplier at 1.0, & avoided the escalation chain, while the fleet kept the surplus inside the company instead of selling it to a third party. That sequence (rule out borrowing on the cap, pool against the penalty, bank the remainder) is the standard FuelEU planning loop.

The FuelEU regime sits alongside EU ETS for shipping & the IMO’s Carbon Intensity Indicator, so a fuel switch that helps the FuelEU balance usually moves the ETS allowance bill too, & the cost cases are best run together. A clean fuel that fixes a FuelEU deficit also cuts EUAs to surrender, but the CII benefit only appears if the switch reduces fuel burn per capacity-mile, which a like-for-like RFNBO swap doesn’t. So the three regimes don’t always pull the same direction, & the planning model has to carry all three rather than assume a fix in one solves the others.

Limitations

Pooling carries counterparty risk that the regulation doesn’t insure. The no-worse-off rule protects a deficit ship’s allocated balance, but it doesn’t protect the commercial deal: if a pool member’s verifier rejects a claimed surplus, the pool total can fall below zero & every ship that relied on it loses its compliance for the year. A pool is only as sound as its weakest verification, & the surplus a deficit ship paid for can evaporate after the transfer price is paid. The allocation methods are also a negotiated matter, not a fixed formula, so the market price for pooled grams is opaque & swings with how many surplus ships are available in a given year.

The 1.1 escalation is uncapped in time, only in magnitude. It tops out at five times the base rate, but a ship that runs a deficit from 2025 onward hits that ceiling & then pays the maximum every year against a target that keeps tightening, so the absolute bill keeps rising even after the multiplier stops growing. The escalation resets on a single compliant year, which sounds generous until you price what one compliant year of RFNBO or pooled surplus costs against a target that moved.

Banking & borrowing have asymmetric limits that catch operators out. Banking is unlimited & open-ended; borrowing is capped at 2% of target-times-energy, available once, & barred in consecutive years. An operator who borrows to cover 2025 & then misses 2026 has no borrowing left, a 1.1-surcharged hole in the 2026 balance from the 2025 advance, & a deficit that now starts the escalation chain. The borrowing window is narrow enough that it shouldn’t be a primary strategy.

The penalty is a cash-flow event, not a fee that scales smoothly. It falls due annually after the verification cycle, in a single payment, on a deficit that for a large operator runs into eight figures. A fleet that switches fuel mid-year still pays on the whole year’s attained intensity, so the timing of a retrofit or a fuel switch matters as much as the switch itself. The administering-authority payment & the FuelEU database registration deadlines are fixed dates, & a missed registration can cost a pool its standing for the year.

The open question the regulation leaves to private contract is who pays. Article 23 names the responsible company, but on a time charter the charterer buys & burns the fuel that determines the intensity while the owner is the company of record for the Document of Compliance. The standard time-charter forms predate FuelEU, so the penalty allocation is set by a FuelEU or emissions clause bolted onto the time charter party, & where no clause exists the liability sits with whichever party the regulation names rather than whichever party controlled the fuel. That mismatch between regulatory liability & commercial control is unresolved across much of the fleet, & it’s the single largest source of FuelEU dispute exposure as the first penalties for 2025 come due in 2026.