Bunker Adjustment Factor (BAF) in Shipping

The Bunker Adjustment Factor (BAF) is a contractual surcharge that adjusts the freight payable on a liner or charter-party shipment to reflect changes in marine fuel prices between the date the freight rate was agreed and the date the voyage is performed. Fuel typically accounts for 30 to 60 percent of the variable cost of operating a deep-sea cargo vessel, depending on speed, fuel grade, and trade-lane distance. BAF allocates the risk of fuel-price movement between the cargo interest and the carrier or shipowner in a transparent, formulaic way. You can compute BAF for a charter-party fixture at the Bunker Adjustment Factor calculator or work through a surcharge scenario at the Bunker Surcharge calculator.

What BAF is and why it exists

Freight contracts and bunker supply contracts don’t naturally align in timing. A liner shipper booking container space eight weeks ahead, or a charterer fixing a dry-bulk voyage from Brazil to Rotterdam, commits to a rate well before the ship lifts fuel. Between fixture and performance, the price of very-low-sulphur fuel oil (VLSFO), low-sulphur marine gas oil (LSMGO), or liquefied natural gas can swing by 20 percent or more in a single quarter; in 2022, VLSFO at Rotterdam moved from around USD 600 per metric tonne in January to above USD 1,100 in June before retracing. Without a contractual adjustment, the carrier absorbs the entire fuel-price risk, which means building a substantial risk premium into base freight during volatile periods.

BAF solves this by separating the fuel component from base freight and tying it to a published price index. A well-drafted clause identifies a transparent reference price, an assumed consumption for the voyage or trade lane, a trigger threshold below which no adjustment fires, and the recalculation interval (monthly, quarterly, or per-voyage). The combination of those parameters determines whether the BAF functions as a genuine cost pass-through or as a second freight rate. That distinction has attracted sustained regulatory attention from the European Commission, the Federal Maritime Commission, and shipper associations for over 30 years.

The same economic problem exists across all charter forms, but the mechanism differs by contract type. In time charter parties, the time charterer buys and pays for bunkers directly, so BAF doesn’t arise; the fuel-price risk sits entirely with the charterer, which is why speed and consumption warranties become the contested commercial battleground instead. In voyage charter parties, the shipowner provides bunkers and prices the voyage freight to recover them, so the question of how to share a post-fixture price movement falls squarely on the escalation clause. In liner container trades, the carrier sets a base freight rate and applies BAF as a separately published surcharge on top.

BAF in liner container shipping

Trade-lane formula structure

Liner BAF is a per-TEU or per-FEU charge, recalculated monthly or quarterly, that flows from a trade-lane formula. The three variables common to every major carrier’s formula are: (1) a fuel-price index expressed as a price per metric tonne, (2) an assumed average fuel consumption per slot on that specific trade lane, and (3) a trade factor that adjusts the slot consumption for round-trip distance and vessel utilization.

The generic formula structure looks like this in KaTeX notation:

where $C_{\text{lane}}$ is the assumed round-trip fuel consumption per slot (metric tonnes per TEU), $P_{\text{index}}$ is the current-period fuel price from the agreed index, $P_{\text{base}}$ is the agreed base price, and $U_{\text{lane}}$ is the assumed slot utilization (as a fraction). When the formula yields a negative number, some carriers apply the adjustment as a reduction; others floor it at zero.

The fuel-price index is most often a basket of published prices at four major bunkering hubs: Rotterdam, Singapore, Fujairah, and Houston. Prices are drawn from Platts Bunkerwire or the Argus Marine Fuels daily assessment, averaged over a defined lag period (typically the month two months prior, so that the BAF for March covers November’s average price). The lag period allows both carriers and shippers to calculate the forthcoming BAF before the trade period opens.

IMO 2020 and the VLSFO transition

The entry into force of MARPOL Annex VI Regulation 14’s 0.50% global sulphur cap on 1 January 2020 forced every carrier to rebenchmark its BAF formula from high-sulphur fuel oil (IFO 380, HSFO) to VLSFO or to a compliant alternative. IFO 380 had been the standard bunker grade for decades; VLSFO trades at a sustained premium over HSFO, a differential that the International Energy Agency put at roughly USD 100 to 200 per metric tonne through 2021 and 2022.

Carriers handled the transition in two ways. Some introduced a separate Low Sulphur Surcharge (LSS) or Marine Fuel Recovery (MFR) charge to cover the VLSFO premium on top of a BAF still denominated in HSFO. Others rewrote their BAF formula from scratch, replacing the HSFO price index with a VLSFO or LSMGO index and adjusting the base price accordingly. The latter approach is cleaner operationally but required carriers to renegotiate the BAF formula with large BCOs under existing service contracts, as many contracts had fixed BAF mechanics that referenced IFO 380 specifically.

Maersk’s 2018 pre-announcement of its “new BAF” methodology was the industry reference point. The formula disaggregated the BAF into a fuel-price component and a published trade factor for each lane, and Maersk published both the consumption assumption and the round-trip distance per lane on its website, allowing shippers to verify the calculation independently. Hapag-Lloyd, CMA CGM, and MSC published analogous methodologies over the following 18 months. The transparency reflected pressure from the European Shippers’ Council and from large BCOs that had started benchmarking carrier BAF structures against each other.

EU ETS and FuelEU Maritime: the post-2024 regulatory layer

Directive (EU) 2023/959 amended Directive 2003/87/EC to include maritime transport in the EU Emissions Trading System from 1 January 2024. The phase-in schedule requires ships covered by the regulation to surrender EU Allowances (EUAs) for a percentage of their verified CO2, CH4, and N2O emissions on voyages within the European Economic Area: 40 percent of verified 2024 emissions, 70 percent of 2025 emissions, and 100 percent from 2026 onward. The regulation applies to ships above 5,000 gross tonnes, and the emissions boundary covers: 100 percent of emissions on voyages between two EEA ports; 50 percent on voyages between an EEA port and a non-EEA port.

EUA prices through 2023 and 2024 ranged between EUR 50 and EUR 100 per tonne of CO2. For a container ship emitting approximately 0.16 tonnes of CO2 per nautical mile at design speed, the ETS cost on, say, a 10,000-nautical-mile Asia-North Europe leg (half counted at 50%) adds a meaningful per-TEU cost that carriers have not historically recovered through BAF.

The carrier response has been varied. Maersk introduced an “Environmental Fuel Fee” (EFF) from 2023 covering both VLSFO cost and the anticipated ETS exposure. Hapag-Lloyd publishes an “Emissions Surcharge” (ES) that tracks EUA forward prices quarterly. CMA CGM and Evergreen have adopted analogous structures under different trade names. Whether these charges constitute a modified BAF or a separate regulatory surcharge is commercially important: contract BAF formulas that predate 2024 generally don’t capture ETS costs unless expressly amended.

FuelEU Maritime, Regulation (EU) 2023/1805, came into force on 1 January 2025. It mandates a progressive reduction in the greenhouse-gas intensity of energy used on board for voyages to, from, and between EU ports: 2 percent below the 2020 fossil-fuel baseline by 2025, rising to 6 percent by 2030 and 80 percent by 2050. Ships that fail to comply pay a penalty equal to the cost of the amount of energy they would have needed to purchase to meet the standard. The penalty is expressed in EUR per GJ of non-compliant energy. Unlike the ETS, which prices actual emissions, FuelEU Maritime penalizes energy-intensity, nudging carriers toward methanol, ammonia, and LNG blends that reduce the GHG intensity of the total fuel mix. Carriers operating bio-LNG or green methanol on EU routes are beginning to fold a “green fuel premium” surcharge into their BAF framework alongside the standard bunker cost component.

Low Sulphur Surcharge variants

The Low Sulphur Surcharge (LSS), Marine Fuel Recovery (MFR), and Environmental Fuel Fee (EFF) are market names for what is functionally an adjustment to the VLSFO/LSMGO premium over the pre-2020 base. The difference between an LSS and an updated BAF is mostly commercial presentation: an LSS is often quoted as a flat per-TEU charge rather than a formula-derived figure, and it resets less frequently than a monthly BAF.

In areas where carriers operate Emission Control Areas (ECAs) under MARPOL Annex VI Regulation 14.3, ships must use fuel with a sulphur content at or below 0.10% m/m (from 1 January 2015 for the North Sea, Baltic Sea, and North American ECAs). The cost premium of LSMGO over VLSFO, which can range from USD 50 to USD 200 per metric tonne depending on the market, is sometimes recovered through a separate ECA surcharge applied only to voyages involving ECA transit legs.

BAF in the liner conference era

Until 18 October 2008, the dominant BAF mechanism in European trades was the conference BAF: a single quarterly figure announced by a liner conference and applied uniformly by all member lines on a trade lane. Conferences held a block exemption from EU competition law under Council Regulation (EEC) 4056/86. The BAF was published openly, usually quarterly, and the transparency was its primary virtue.

The criticism came from the European Shippers’ Council and from the European Commission, which concluded in its review under the terms of Council Regulation (EC) 1419/2006 that the BAF mechanism, while not the primary antitrust concern of liner conferences, constituted price coordination on an essential element of freight. Regulation (EC) 1419/2006 repealed the block exemption with effect from 18 October 2008. The conference BAF as a coordinated figure ceased to be lawful in EU trades from that date.

The legacy is that shippers retained the expectation of a published, formulaic BAF. Most major carriers continued to publish unilateral BAFs after 2008, taking individual responsibility for their formulas rather than coordinating them. This preserved the informational function of the conference BAF while removing the coordination element that Article 101 of the Treaty on the Functioning of the European Union prohibits.

Comparison: liner BAF vs. charter-party bunker clause

Bunker recovery in voyage charters: GENCON and bespoke clauses

In the dry-bulk spot market, the voyage charter party is almost always fixed on a BIMCO GENCON form or a trade-specific equivalent. The GENCON 94 form contains Clause 17 as an optional bunker-clause rider permitting parties to attach a Bunker Adjustment Clause by agreement. GENCON 2022, revised and published by BIMCO, modernized several provisions but retained the principle that bunker adjustments are optional riders rather than standard clause text, reflecting the voyage market’s preference for bespoke drafting.

A typical bespoke voyage-charter escalation clause sets a base price (agreed at fixture), references a price index for a specified grade at a specified port, selects an averaging period of three to five business days before the bill of lading date, and states the adjustment rate in USD per freight tonne per USD 10 change in bunker price per metric tonne. For example: “for every USD 10 per metric tonne by which the average Platts Singapore VLSFO assessment for the five business days preceding the bill of lading date exceeds USD 700, freight shall increase by USD 1.50 per metric tonne of cargo.” The same formula applies in reverse if the index falls below the base.

Common rider amendments post-2020 include: switching the index from IFO 380 to VLSFO or LSMGO; adding a cap and collar to limit carrier windfall and shipper overexposure at extreme price levels; replacing Bunkerworld with Platts Bunkerwire or Argus Marine Fuels as the reference; and narrowing the averaging window from one week to five business days for greater precision. The GENCON bunker clause interacts with the demurrage clause: an escalation clause that runs to settlement at outturn freight should not inadvertently affect the demurrage rate, which in GENCON 94 Clause 7 is a daily rate linked to freight per bill of lading day.

NYPE 2015 (the New York Produce Exchange form revised in 2015) is the standard time-charter form for dry-bulk and general-cargo vessels. Because the time charterer takes on bunker responsibility under NYPE, Clause 9 deals not with escalation but with the agreed quantities and prices at delivery and redelivery. NYPE 2015 Clause 9 requires the owner and charterer to agree the price of bunkers on board at delivery, with redelivery at the same price, creating a symmetric bunker purchase and resale. This doesn’t function as a BAF in the traditional sense; rather, it ensures the owner doesn’t profit or lose from the bunker-price differential between delivery and redelivery.

BIMCO Bunker Price Adjustment Clauses 2015

BIMCO published its current standard Bunker Price Adjustment Clause for Time Charter Parties and its companion Bunker Price Adjustment Clause for Voyage Charter Parties with revisions effective 2015. Both clauses are available from the BIMCO website and are designed to be incorporated by reference into any BIMCO-approved charter form.

The architecture of both clauses follows four steps. First, the parties agree and record a base price per metric tonne for each fuel grade used on the vessel. Second, the clause defines the agreed index: typically the Platts Rotterdam or Singapore daily assessment, averaged over a specified period. Third, the clause specifies an adjustment threshold: the clause fires only when the index price exceeds or falls below the base by a defined amount (commonly USD 25 or USD 50 per metric tonne), preventing de minimis adjustments from generating invoice friction. Fourth, the clause states the calculation formula explicitly, producing an adjustment in USD per day (for time charters) or in USD per freight unit (for voyage charters).

A distinguishing feature of the BIMCO voyage clause is that the adjustment is part of freight, not a separate line item. This simplifies tax treatment, avoids the need for a separate invoice, and prevents complications in letter-of-credit presentations where the LC is drawn against the freight invoice. The BIMCO time-charter clause settles the adjustment with the hire statement, added or deducted from the monthly hire installment.

The BIMCO clauses are designed to interlock with the BIMCO Bunker Quality and Liability Clause 2022 and the BIMCO Sulphur Content Clauses for Time and Voyage Charter Parties 2018. The Sulphur Content Clauses, revised to reflect MARPOL Annex VI Regulation 14’s 0.50% global cap, allocate the cost of compliant fuel between owner and charterer and specify which party bears the premium for ECA-compliant fuel on ECA transit legs. Together, these three clauses form a consistent framework for bunker quality and ISO 8217 compliance, price escalation, and sulphur compliance.

The 2015 revisions addressed two gaps in the earlier 2008 text: they added express mechanics for the transition between fuel grades (important now that VLSFO has largely replaced HSFO at sea) and they aligned the index references with the post-2008 market practice of using Platts or Argus rather than Bunkerworld. BIMCO has not yet published a further revision addressing EU ETS costs, and there is active discussion in the industry about whether the existing clauses need a new rider to bring EUA costs within the escalation framework.

FMC regulation and US law

In the United States, liner surcharges including BAF are governed by the Shipping Act of 1984 as amended by the Ocean Shipping Reform Act 2022 (OSRA 2022). The Federal Maritime Commission (FMC) requires ocean common carriers to publish their tariffs, including all surcharges, and to give adequate notice of changes. OSRA 2022 strengthened the FMC’s authority to review complaints about unreasonable practices, including surcharges that bear no reasonable relationship to costs, and it created new rules on detention and demurrage billing. The OSRA 2022 final rules, which the FMC phased in through 2023 and 2024, did not set a specific cap on BAF levels but reaffirmed that carriers must be able to substantiate the cost basis of surcharges on request.

The FMC’s 2022 Implementation Report documented shipper complaints about the proliferation of surcharges during the post-COVID capacity crunch of 2021 to 2022, when aggregate surcharges on some Asia-US West Coast trades temporarily exceeded the base ocean freight itself. The FMC initiated a review of surcharge reasonableness but stopped short of mandating a specific formula structure for BAF. The practical consequence is that US carriers publishing a BAF need a defensible cost-based methodology even if it isn’t filed in detail with the FMC.

Antitrust limits on BAF coordination

BAF sits at a delicate intersection of competition law. In EU trades, any coordination of BAF levels among carriers is potentially a violation of Article 101 TFEU now that the liner conference block exemption has been gone for over 15 years. The European Commission’s 2022 review of the Consortia Block Exemption Regulation (CER) ultimately renewed the CER to April 2024 on a transitional basis, after which it expired. The Commission’s ongoing review of competition in maritime transport does not grant any exemption for coordinating surcharge levels; each carrier must set its own BAF independently.

BIMCO’s standard clauses and the publication of carrier BAF methodologies are not, in themselves, antitrust problems: BIMCO produces standardized clause language (parallel to how ISDA produces master agreements for derivatives), and individual carriers publishing their own formulas publicly are not coordinating with each other. The line is crossed when carriers agree among themselves on the level of the BAF, on the timing of BAF announcements, or on a common index that produces de facto price parity. The European Commission’s investigations into container shipping, including the 2016 Statement of Objections against four major carriers concerning coordinated capacity deployment, illustrate how closely the sector is watched.

Fuel hedging as complement or substitute

A growing minority of large shippers and carriers manage bunker exposure through hedging, either alongside BAF or in place of it. Marine fuel doesn’t have a deeply liquid futures market equivalent to crude oil, but the Singapore Exchange (SGX) paper market for VLSFO and HSFO has matured since the 2020 sulphur cap, and ICE Rotterdam barges provide a usable proxy for Atlantic hedging. Carriers and shippers can enter bunker swaps with a counterparty bank or oil trader, fixing an agreed price per metric tonne for an agreed quantity over an agreed period.

Hedging converts bunker price risk into a known cost. It removes the economic need for BAF from the hedging party’s perspective, but it introduces basis risk: the swap index may not track the actual purchase price exactly, especially in smaller ports or during supply disruptions. A carrier that has hedged its fuel exposure but continues to apply BAF will over-recover if the market falls; a shipper that has hedged but is still charged BAF double-pays for protection it has already bought. Sophisticated long-term service contracts between BCOs and carriers increasingly include “hedge harmless” provisions or expressly tie BAF to zero when either party confirms a covering hedge.

The interaction between hedging, BAF, and the EU ETS is still evolving. EUA prices are hedgeable through the EU carbon market, but the forward curve for EUAs doesn’t directly map onto BAF formulas designed for fuel-price escalation. Carriers that want to recover ETS costs through their BAF or EFF need a separate EUA-price component in the formula, and this creates a two-commodity escalation problem (fuel price plus carbon allowance price) that standard BAF templates weren’t designed to handle.

Common dispute patterns

Disputes around BAF cluster in three contexts.

In voyage-charter arbitrations, the most frequent source of conflict is ambiguity in the escalation clause: uncertainty about which index applies, which fuel grade, which averaging period, or what happens when the named index ceases publication. London Maritime Arbitrators Association (LMAA) tribunals have applied the contra proferentem rule against the owner as drafter in numerous awards where the clause wording was unclear. The practical lesson is that bespoke escalation clauses must identify the fuel grade by specification (e.g., “ISO 8217:2017 Annex A Table 2 RMG 380”), the index publisher by full name, the averaging period in calendar or business days, and the fallback index if the primary source fails.

In US liner disputes, the most common allegation is that the carrier applied BAF in a way that deviated from its published tariff or that the BAF level bore no reasonable relationship to actual fuel costs. These disputes can become class actions under the Shipping Act, and the FMC’s complaint mechanism runs parallel to federal court jurisdiction. OSRA 2022 strengthened the tools available to shippers, particularly by expanding the FMC’s authority to issue cease-and-desist orders and to assess civil penalties.

The third context is the interaction of escalation clauses with force majeure in shipping and with sanctions events. Where bunker prices spike because of a sanctions-driven supply disruption, the question of whether the escalation clause captures the spike fully, partially, or not at all has generated sharp commercial disagreement. English courts have treated escalation clauses on their plain wording without implying a sanctions exception. A carrier relying on an escalation clause to recover a sanctions-driven price spike will succeed if the clause wording is broad enough; a clause that references a specific named price source that ceases to publish because of sanctions leaves both parties in dispute about the fallback.

BAF and carbon surcharges after 2025: the emerging framework

The period from 2024 onward has layered at least three regulatory cost streams onto the traditional bunker-cost-only BAF: the EU ETS obligation, the FuelEU Maritime energy-intensity obligation, and the Carbon Intensity Indicator (CII) regime under MARPOL Annex VI Chapter 4 (applicable to ships of 5,000 GT and above from 1 January 2023). CII doesn’t impose a direct financial cost, but carriers managing a fleet CII rating will adjust speeds or routes to preserve their rating, which affects fuel consumption and therefore the consumption assumption underpinning the BAF formula.

A carrier whose fleet CII rating degrades from C to E has two regulatory paths under MARPOL Annex VI Regulation 28: submit a corrective action plan to the flag state, or face port-state control attention. Neither path imposes an explicit per-tonne surcharge, but the operational measures taken to recover the rating (slow steaming, port calls at green-corridor ports, biofuel blending) change the cost structure that the BAF is meant to pass through.

Green methanol, bio-LNG, and ammonia-fueled vessels are entering service from 2024 onward, and the fuel-cost structure of these alternatives is fundamentally different from VLSFO: the energy cost per unit distance is higher, the carbon intensity is lower, and the production supply chain introduces upstream price volatility that doesn’t track the marine fuel oil market. Several carriers have publicly stated their intention to apply a “green fuel premium” or “biofuel surcharge” on voyages operated by these vessels, creating a new BAF-adjacent charge that existing standard clauses don’t cover.

BIMCO and the International Chamber of Shipping have both published guidance noting that existing BAF clauses, including BIMCO’s own 2015 forms, were not designed to accommodate multi-fuel cost structures. Parties amending or drafting new escalation clauses from 2025 onward should address: the fuel grade and specification explicitly, the index source for each grade, how EUA costs are allocated, how FuelEU Maritime compliance costs are allocated, and whether biofuel blends or alternative fuels change the consumption assumption.

Limitations

BAF’s core limitation is that it’s only as good as its formula. A formula that rests on opaque consumption assumptions, an index the shipper can’t verify independently, or a recalculation lag that consistently overshoots or undershoots actual costs becomes a friction point rather than a risk-allocation tool. Carriers have an informational advantage over shippers on actual fleet fuel consumption, which is why regulatory and shipper pressure has consistently pushed toward disclosure of the trade-lane consumption assumption and the index source.

Second, BAF as traditionally designed doesn’t capture regulatory-cost volatility. The EU ETS price has ranged from EUR 25 to EUR 100 per tonne of CO2 within a single calendar year; that volatility is unrelated to physical fuel-price movements and won’t be captured by a BAF indexed to VLSFO. Carriers that use their BAF surcharge to recover ETS costs are either over-recovering when EUAs are cheap or under-recovering when they’re expensive, unless the formula explicitly includes an EUA-price component.

Third, BAF interacts badly with force-majeure and sanctions events. An escalation clause that mechanically passes through an extreme price spike driven by a geopolitical event, rather than by supply and demand fundamentals, can produce commercially absurd results; both parties may have expected the clause to track normal market movements, not wartime disruption. English law doesn’t imply a reasonableness limitation into commercial escalation clauses, so the plain wording governs.

Fourth, hedging creates a structural tension with BAF. When one party has hedged its bunker exposure, applying BAF produces a double-recovery or a double-payment depending on which party hedged. Contracts that don’t address this interaction leave the parties in a dispute about the economic purpose of the BAF provision when both sides have priced the risk differently.

Fifth, BAF formulas calibrated on pre-2020 fuel grades (IFO 380) haven’t all been updated for post-2020 practice. A contract that still references IFO 380 Bunkerworld Rotterdam as the index after January 2020 creates a grade mismatch: the vessel is burning VLSFO at a different price, but the escalation formula continues to reference a grade the vessel no longer uses. Courts and arbitrators have resolved these mismatches differently depending on whether the mismatch is treated as a drafting error correctable by construction or as an ambiguity requiring extrinsic evidence.

Worked example: voyage-charter BAF calculation

A worked example clarifies the mechanics. A Capesize voyage is fixed from Dampier, Western Australia, to Qingdao, China, with a freight rate of USD 9.50 per metric tonne of iron ore. The parties agree a bunker escalation clause with a base VLSFO price of USD 650 per metric tonne, referenced to the Platts Singapore VLSFO assessment averaged over the five business days preceding the bill of lading date, with a USD 1.50 per freight tonne adjustment per USD 10 per metric tonne of bunker movement.

At the bill of lading date, the Platts Singapore five-day average VLSFO price is USD 710 per metric tonne. The bunker price has moved USD 60 above the base.

The adjusted freight is USD 9.50 + USD 9.00 = USD 18.50 per metric tonne. For a cargo of 165,000 metric tonnes, the freight bill is USD 3,052,500 rather than the base USD 1,567,500: the escalation clause has increased the freight by 94 percent. This example is intentionally extreme to show how sharply an uncapped clause can swing in a high-volatility environment, which is why cap-and-collar provisions matter.

If the parties had instead agreed a collar of USD 50 and a cap of USD 100 on the bunker movement that triggers the BAF, the clause would fire on the full USD 60 differential (within the collar), and the adjustment would be USD 9.00 per freight tonne as calculated. Had the movement been USD 130, the cap would have limited the adjustment to $\frac{100}{10} \times 1.50 = \text{USD } 15.00$ per freight tonne, leaving the carrier with USD 30 of unrecovered bunker-price increase per metric tonne of fuel consumed.

The voyage fuel consumption on a loaded Capesize passage from Dampier to Qingdao is roughly 8,000 to 9,000 metric tonnes of VLSFO at design speed. At USD 30 per tonne of unrecovered exposure, the cap costs the owner approximately USD 240,000 to USD 270,000 on a single voyage, which is the price of predictability for the shipper. Charterers can use the Bunker Stem: Optimal Quantity calculator to model the consumption-quantity side of this calculation, and the voyage bunker cost calculator to price a leg’s consumption from speed and distance directly.

Surcharge proliferation and the all-in rate trend

The liner container sector between 2020 and 2024 produced a textbook case of surcharge proliferation. On many Asia-Europe strings, the total of named surcharges in 2022 exceeded the base ocean freight component. The named charges in a typical booking confirmation during that period included: Base Ocean Freight (BOF), Bunker Adjustment Factor (BAF), Low Sulphur Surcharge (LSS), Environmental Fuel Fee (EFF), Emission Control Area surcharge (ECA), Currency Adjustment Factor (CAF), Terminal Handling Charge (THC), Documentation Fee, Advance Manifest System fee (AMS, US only), Entry Summary Declaration fee (ENS, EU only), Destination Delivery Charge (DDC), Inland Haulage, and, from late 2023, a Suez Diversion or Red Sea Surcharge following Houthi attacks on merchant vessels in the southern Red Sea.

The UNCTAD Review of Maritime Transport, published annually, has documented this pattern since 2016. The 2023 edition noted that the average Asia-Europe contracted rate for large BCOs in 2022 and 2023 included a surcharge component representing between 40 and 60 percent of the total shipped cost, depending on the specific lane and the shipper’s negotiating position. The figures vary by lane and contract vintage; the UNCTAD report draws on published rate data rather than confidential service-contract terms.

Shippers responded in two ways. Large BCOs with enough volume to negotiate directly began demanding all-in contracted rates that fixed the total per-TEU cost inclusive of all surcharges, with any regulatory pass-through (ETS, port congestion) as the only permitted variable. UNCTAD’s 2023 data showed that BCOs representing more than 10,000 TEU per year per carrier increasingly demanded all-in pricing. Smaller shippers, buying in spot or near-spot markets, had less negotiating power and continued to face itemized surcharge lists.

Regulatory pressure reinforced the commercial trend. The FMC’s OSRA 2022 implementation rules, which took effect in 2023, clarified that carriers must provide shippers with adequate notice before applying a new surcharge or increasing an existing one, and that surcharges must bear a reasonable relationship to costs. The European Commission’s sector inquiry into container shipping, initiated in 2022, specifically examined whether named surcharges were cost-reflective or served as disguised price coordination. No formal enforcement action had been concluded at the time of writing, but the scrutiny has nudged carriers toward greater formula transparency.

BAF in contracts of affreightment and industrial trades

Contracts of affreightment (COAs) are long-term volume agreements under which a carrier commits to carry a specified quantity of cargo per period at a stipulated freight rate, without committing to specific vessels in advance. In dry-bulk COAs for commodities like coal, iron ore, and grain, BAF-style escalators are standard. The structure is similar to the voyage-charter escalation clause, but the recalculation interval is typically monthly or quarterly over the contract term (which may run two to five years), and the trigger threshold is set higher to avoid monthly invoice friction on a high-volume contract.

Industrial shipping contracts, used by oil majors, mining companies, and grain traders for dedicated parcelling or partial-charter work, commonly incorporate the BIMCO Bunker Price Adjustment Clause for Voyage Charter Parties 2015 by reference, sometimes with riders adapting the base price and the index to reflect the counterparty’s own bunker procurement practice. A mining company that buys bunkers on a term contract from an oil major will sometimes negotiate a “cost-plus” BAF that references its actual procurement price rather than a market index, which eliminates the basis risk between the market index and the actual purchase price but requires the shipper to share its procurement cost with the carrier, which not all counterparties are willing to do.

The Sea Cargo Charter, published by a coalition of 18 major bulk-commodity charterers in 2020 and updated in 2021 and 2023, includes provisions on emissions-aligned chartering that touch on fuel and BAF. While the Sea Cargo Charter framework doesn’t mandate a specific BAF clause, its trajectory-alignment requirement encourages charterers to include decarbonization language in bunker clauses so that owners are incentivized to use lower-carbon fuels over the life of a multi-year COA.

Historical development of BAF

BAF as a named surcharge dates to the early 1970s oil price shocks. Before the 1973 OPEC embargo, bunker fuel prices were sufficiently stable that carriers priced the fuel cost into the base freight rate and absorbed modest inter-quarter movements as a normal cost of business. The tripling of oil prices between 1973 and 1974, and then the second price shock of 1979 to 1980, made this practice commercially unsustainable for carriers on long-term contracts.

Liner conferences, which coordinated freight rates across member lines under the block exemptions available in most jurisdictions, were the mechanism through which BAF was standardized in the late 1970s. The conference adopted a uniform bunker price reference, a uniform consumption assumption for the trade lane, and a uniform quarterly recalculation schedule. The transparency was genuinely useful: shippers could calculate the next quarter’s BAF from publicly available oil price data and the published conference formula. The BAF moved in parallel across all member lines because the conference set it, which is also why it attracted competition-law scrutiny.

When oil prices collapsed in 1986, carriers faced the reverse problem: the BAF generated deductions from base freight, which in several conference trades produced negative all-in rates on some lanes. Conferences responded by introducing floors and by recalibrating base prices upward. The precedent of managing the formula to protect carrier economics, rather than to pass through costs symmetrically, fed the long-run shipper suspicion that BAF was never purely cost-reflective.

Through the 1990s and into the 2000s, the pattern was stable: quarterly BAF announcements from conferences (or from lead carriers acting as de facto conference coordinators after many conference functions had been curtailed), adjustment ranges of USD 20 to 80 per TEU, and periodic disputes about over-recovery. The formal end of conference BAF coordination in the EU in October 2008 marked the transition to the carrier-specific methodology era, but the economics and the formula structure were inherited largely intact.

Charter party speed, consumption, and the BAF interaction

In time charter parties, the time charterer’s bunker liability is defined by the speed and consumption warranties in the charter. NYPE 2015 Clause 24 (the speed and consumption clause) sets out the owner’s warranted sea speed and daily fuel consumption at that speed, the consumption in port on generators, and the consumption at idle. The charterer pays for actual bunkers purchased; the owner’s warranty protects the charterer against a vessel that consumes more than the warranted quantity.

There’s no BAF in a standard time charter because the charterer bears the fuel-price risk directly. But the speed and consumption warranty interacts with the fuel-price environment in a way that creates equivalent commercial tension: when VLSFO prices are high, the charterer has a strong economic incentive to slow-steam the vessel to reduce consumption, but slow-steaming may conflict with the owner’s right to withdraw the vessel for off-hire or with sub-charterers’ scheduling requirements. The Charter Party Speed and Consumption Warranties article covers the warranty framework in detail.

In a voyage charter, the owner provides and pays for bunkers as part of the voyage freight. The owner’s fuel-price exposure is what the BAF clause addresses. If the owner has warranted a specific consumption per day to the charterer (a consumption-efficiency warranty sometimes included in voyage charters), then over-consumption relative to the warranty creates a loss that the BAF doesn’t help recover: the BAF adjusts for price, not for the quantity burned above the warranted rate. Owners drafting bespoke voyage escalation clauses should therefore distinguish clearly between price-escalation provisions (BAF) and consumption-overrun provisions (which belong in a separate warranty clause).

See also

Calculators

• Bunker Adjustment Factor (BAF)
• Bunker Surcharge
• Charter Clause: GENCON 1994 Cl. 5
• Charter Clause: NYPE Cl. 35
• Bunker Stem: Optimal Quantity
• Tanker Op: Bunker Delivery Note
• Bunker Survey: Wedge Formula

Related wiki articles

• Voyage Charter Party
• Time Charter Party
• Bunker Quality and ISO 8217
• MARPOL Convention
• IMO 2020 Sulphur Cap
• Sea Cargo Charter
• Force Majeure in Shipping
• Demurrage
• Reversible Laytime and Despatch
• Charter Party Speed and Consumption Warranties