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FONAR and BDN Documentation

The Fuel Oil Non-Availability Report (FONAR) and the Bunker Delivery Note (BDN) are the two principal documents of marine fuel quality and compliance evidence under MARPOL Annex VI. The BDN is the mandatory document accompanying every fuel delivery to a vessel, recording the fuel quality parameters (sulphur content, density, viscosity, water content, flashpoint, sediment, fuel category) that establish the baseline for compliance under MARPOL Annex VI Regulation 18.5, the EU MRV Regulation, FuelEU Maritime (which adds WtW intensity reporting), the IMO Net-Zero Framework GHG Fuel Intensity (GFI) and the EU ETS for shipping. The FONAR is a vessel master’s documented declaration that compliant low-sulphur fuel was not available at a planned bunker port, providing a temporary defence against IMO 2020 sulphur cap non-compliance under MARPOL Annex VI Regulation 18.2 (which requires owners to demonstrate they could not obtain compliant fuel despite best efforts) and is reviewed by the relevant port-state-control authority and flag-state administration. Both documents are reviewed by port-state-control inspectors under the Paris MoU, Tokyo MoU, IndianOcean MoU, Black Sea MoU, Caribbean MoU, Mediterranean MoU, Vina del Mar Agreement and Riyadh MoU regional inspection regimes. Both are subject to three-year retention requirements onboard the vessel. ShipCalculators.com hosts the principal computational tools: the BDN compliance check calculator, the FONAR submission calculator, the bunker representative sample volume calculator, the FuelEU BDN parser calculator, the WtW intensity calculator and the GFI compliance calculator. A full listing is available in the calculator catalogue.

Contents

Bunker Delivery Note (BDN)

Regulatory basis

The BDN requirement is established by MARPOL Annex VI Regulation 18.5, which requires the bunker fuel supplier to provide a delivery note to the vessel at the time of fuel delivery, recording the principal fuel quality parameters. The BDN must be:

  • Provided to the vessel before bunker transfer is completed (best practice; the regulation requires “at the time of delivery” but practical implementation usually means before the bunker barge departs).
  • Signed by the bunker supplier representative and by the vessel’s chief engineer or designated officer.
  • Retained onboard the vessel for at least three years from the date of delivery.
  • Available for port-state-control inspection.

BDN content (mandatory minimum under MARPOL)

The mandatory BDN content under MARPOL Annex VI Regulation 18.5 includes:

  • Vessel name and IMO number.
  • Port and date of delivery.
  • Quantity of fuel delivered (in metric tonnes).
  • Density at 15 °C.
  • Sulphur content (% mass/mass).
  • Statement on flash point (above the relevant SOLAS limit, typically 60 °C for residual fuel, 43 °C for distillate).
  • Bunker supplier name and address.
  • Statement that the fuel meets the requirements of MARPOL Annex VI Regulations 14 and 18.3.

BDN content (extended under voluntary and regional standards)

In practice, BDNs typically include extended content beyond the MARPOL mandatory minimum, conforming to the ISO 8217 marine fuel specifications standard. Extended content includes:

  • Viscosity at 50 °C (for residual fuels) or at 40 °C (for distillates).
  • Water content (% volume).
  • Sediment (% mass).
  • Pour point.
  • Cloud point (for distillates).
  • Cetane index or cetane number (for distillates).
  • Aromatic content.
  • Catalyst fines (Aluminium + Silicon, mg/kg) (a critical parameter for HFO; high cat fines cause severe engine wear).
  • Vanadium content (an indicator of HFO quality).
  • Calcium, sodium, zinc, phosphorus (metallic contaminants).
  • Acid number.
  • Hydrogen sulphide (H2S) at the headspace of the bunker tank.

BDN content (FuelEU Maritime, IMO Net-Zero Framework)

For vessels subject to FuelEU Maritime, the BDN must additionally include:

  • Certified WtW intensity (g-CO2eq/MJ): where available from the bunker supplier; otherwise the vessel uses the FuelEU Annex II default value for the fuel category.
  • Certified WtT intensity and TtW emission factors: separately reported.
  • Fuel category per FuelEU classification (HFO, VLSFO, LSMGO, MGO, LNG, methanol, ammonia, biofuel sub-category, RFNBO sub-category, etc.).
  • RFNBO certification (if applicable): scheme name (ISCC EU, REDcert, RSB, Bonsucro), batch identifier, additionality and temporal correlation status.
  • Pilot fuel content (for dual-fuel deliveries).
  • Methane content (for LNG bunkers).
  • Biofuel content (for blended fuels).

For vessels subject to the IMO Net-Zero Framework (from 2027), the BDN must include the IMO LCA Guidelines (MEPC.391) certified WtW intensity and any applicable verifier scheme references.

Bunker representative sample

Alongside the BDN, representative samples of the delivered fuel must be drawn during the bunker transfer:

  • Samples are taken at the receiving end of the bunker hose (not at the supplier’s tank), in accordance with the IMO MARPOL sampling procedure (MEPC.182(59) and amendments).
  • Sample bottles are typically four: one for the vessel, one for the supplier, one held by an independent third party (often the bunker surveyor), and one for any port-state inspection.
  • Sample volume: typically 400 mL to 750 mL per bottle.
  • Sealing: each sample is sealed with a tamper-evident seal in the presence of all parties; the seal numbers are recorded on the BDN.
  • Retention: vessel sample is retained for at least 12 months under MARPOL; some flag administrations require longer retention.

The samples are the principal evidence in any subsequent dispute about fuel quality (off-spec deliveries, sulphur exceedances) and are tested by accredited laboratories (FOBAS, DNV, Veritas Petroleum Services, Inspectorate, SGS, Intertek, Bureau Veritas) when required.

IMO standard BDN format

The IMO has established a standard BDN format under MEPC.1/Circ.792 (and updates). The standard format provides a consistent layout that facilitates port-state-control inspection and electronic data exchange. Most major bunker suppliers (Shell, BP, Vitol, Trafigura, OW Bunker successors, Aegean, Bunker One, Monjasa, Peninsula, Hin Leong successors, Chimbusco, Sinopec) use the IMO standard format with their own branding.

Electronic BDN

The IMO is developing standards for electronic BDN (eBDN) to replace the paper-based system. The expected benefits are reduced administration, improved data accuracy, and better integration with the FuelEU Maritime, IMO Net-Zero Framework and EU ETS reporting systems. Pilot eBDN deployments have been undertaken in Singapore, Rotterdam, Antwerp and Hong Kong since 2020; commercial rollout is expected from 2025 to 2027.

The Singapore Maritime and Port Authority (MPA) Mass Flow Meter (MFM) bunker delivery scheme (in force 2017) is the principal operational eBDN system, replacing the historic dipping-based volumetric measurement with mass-flow-meter-based mass measurement for greater accuracy. The MPA system is being replicated in Rotterdam (rolling out 2024), and is referenced as a model by ARA (Antwerp-Rotterdam-Amsterdam) ports and Hong Kong.

BDN disputes and off-spec deliveries

Bunker quality disputes are common in marine practice. Typical issues include:

  • Sulphur exceedance: BDN reports lower sulphur than actual delivered fuel, jeopardising compliance with IMO 2020 sulphur cap, Emission Control Areas limits or local port limits.
  • Catalyst fines exceedance: high catalyst fines cause rapid engine wear; ISO 8217 limit is typically 60 mg/kg (DM grades) or 80 mg/kg (RM grades).
  • Viscosity discrepancy: deviation from BDN-specified viscosity affects atomisation and combustion.
  • Water contamination: water above the BDN limit causes injection problems and engine wear.
  • Density manipulation: incorrectly high BDN density results in less actual fuel delivered (the vessel pays per metric tonne but receives less fuel by volume than the BDN suggests).

Disputes are typically resolved through:

  • Independent laboratory testing of the retained samples (turnaround typically 7 to 14 days).
  • Bunker insurance (offered by several P&I clubs and specialist insurers) covers the cost of off-spec deliveries.
  • Arbitration under the bunker supply contract terms (often London or Singapore arbitration).
  • Port-state-control intervention for sulphur exceedance affecting MARPOL compliance.

BDN and PSC inspection

Port-state-control (PSC) inspectors routinely check:

  • BDN retention: presence of all BDNs from the past three years.
  • BDN signatures: present from both supplier and vessel.
  • Sulphur content: matching the operational profile (e.g. ECA-compliant fuel for ECA voyages).
  • Sample availability: sealed samples present onboard.
  • BDN-to-fuel-tank-traceability: clear link between BDN and the fuel tank in which the delivered fuel was stored.
  • Engineering log entries: matching fuel consumption to BDN deliveries.

Deficiencies in BDN documentation are a common PSC finding; serious deficiencies (sulphur exceedance, missing BDNs, evidence of falsification) can result in vessel detention.

Fuel Oil Non-Availability Report (FONAR)

Regulatory basis

The FONAR is established by MARPOL Annex VI Regulation 18.2, which provides:

  • The vessel master must demonstrate that compliant fuel was not available at the planned bunker port.
  • The vessel must demonstrate best efforts to procure compliant fuel.
  • The vessel must report the non-availability to the flag administration and to the competent port authority at the next port of call.

When FONAR applies

FONAR applies when:

  • A vessel arrives at a port within an ECA (Emission Control Area) or in an EU/Mediterranean SECA (Sulphur Emission Control Area) without having loaded compliant fuel because compliant fuel was not available at the previous bunker port.
  • A vessel is operating in territory subject to a local 0.10% sulphur limit (e.g. EU ports beyond ECA, CARB at-berth rule, Hong Kong, mainland China port controls) without compliant fuel due to non-availability.
  • A vessel is operating subject to the global IMO 2020 sulphur cap of 0.50% sulphur without compliant fuel.

FONAR content (per IMO MEPC.1/Circ.881)

The IMO standard FONAR format under MEPC.1/Circ.881 (revised from the original Circ.864) includes:

  • Vessel particulars: name, IMO number, flag, type, gross tonnage, deadweight.
  • Voyage details: previous port, planned next port, planned arrival date.
  • Planned bunker port: at which compliant fuel was sought.
  • Bunker suppliers contacted: list of suppliers from whom compliant fuel was sought, with dates of inquiry and responses.
  • Reason for non-availability: e.g. “compliant fuel out of stock”, “compliant fuel not available at this port”, “compliant fuel only available with multi-day delivery delay”.
  • Best efforts demonstration: documentary evidence of the inquiries made (emails, broker confirmations, supplier responses).
  • Operational impact: amount of non-compliant fuel intended to be used, sulphur content, ports through which the non-compliant fuel will be burnt.
  • Mitigation measures: alternative actions considered (route deviation, lay-time, slow steaming).
  • Master signature and date.

FONAR review and acceptance

The FONAR is submitted to:

  • The flag administration of the vessel.
  • The port authority at the first port of arrival in the relevant compliance zone.

The flag administration and port authority may:

  • Accept the FONAR (the vessel is deemed compliant under MARPOL Regulation 18.2 for the period of demonstrated non-availability).
  • Reject the FONAR (the vessel faces non-compliance proceedings, potentially including fines, vessel detention, or master/owner sanctions).
  • Conditionally accept the FONAR (acceptance with specific conditions, e.g. requirement to bunker at next available compliant port).

Practice across flags and ports varies significantly. Some flag administrations (e.g. Marshall Islands, Liberia, Panama, Singapore) have well-established FONAR review procedures; others have ad hoc procedures. Some port authorities (Singapore, Rotterdam, Hamburg, Long Beach, Hong Kong) routinely review FONARs; others (smaller ports) may not have a dedicated review process.

FONAR limitations

FONAR is intended as an exceptional defence, not as a routine planning tool. Repeated FONARs from the same vessel or owner trigger increased scrutiny and can result in rejection of subsequent FONARs even where the underlying non-availability is genuine. Owners are expected to:

  • Plan voyages with compliant fuel availability at planned bunker ports.
  • Maintain alternative bunker contingency plans (alternative ports, alternative suppliers, alternative routings).
  • Hold strategic reserves of compliant fuel for short-notice contingencies.

FONAR and the IMO 2020 transition

The FONAR mechanism was particularly important during the IMO 2020 transition (October 2019 to early 2021), when global compliant fuel availability was constrained as the supply chain reorganised to deliver VLSFO and LSMGO at scale. During this period:

  • Approximately 20,000 to 40,000 FONARs were submitted globally per year (peak in early 2020).
  • Acceptance rates were generally high (approximately 80 to 90%).
  • Rejection cases were typically due to inadequate documentation or repeated FONARs from the same vessel.

By 2022 and beyond, the global compliant fuel supply chain had stabilised and FONAR submissions fell to approximately 2,000 to 5,000 per year globally.

FONAR and FuelEU Maritime / IMO Net-Zero Framework

FONAR is a sulphur-cap defence, not a WtW intensity defence. There is no analogous FONAR-style defence under FuelEU Maritime or the IMO Net-Zero Framework GFI. For FuelEU and GFI, vessels remain subject to the intensity calculation regardless of fuel availability; non-compliance must be remedied through pooling, banking, or penalty payment.

This asymmetry is a recognised concern for owners operating in regions with limited RFNBO or low-carbon fuel availability. The European Commission has indicated it will monitor FuelEU Maritime implementation and may consider additional flexibility mechanisms if compliant fuel availability is constrained, but as of end-2024 no such mechanism is in place.

BDN and FONAR in regulatory chain

BDN as evidence baseline

The BDN provides the evidence baseline for downstream compliance calculations:

  • MARPOL Annex VI Regulation 14: sulphur content for ECA / global cap compliance.
  • MARPOL Annex VI Regulation 22A: SEEMP and CII calculations require fuel consumption from BDNs.
  • EU MRV Regulation: annual fuel consumption and CO2 emissions calculated from BDN data.
  • IMO DCS: similar to EU MRV, fleet-wide fuel consumption reporting.
  • EU ETS for shipping: EUA surrender obligation calculated from BDN-derived fuel consumption on EU voyages.
  • FuelEU Maritime: WtW intensity calculation requires BDN-certified WtW intensity for each delivery.
  • IMO Net-Zero Framework GFI: similar to FuelEU but applied globally.

The BDN therefore underpins essentially all marine fuel-based compliance calculations. Errors or omissions in the BDN propagate into compliance reporting; the integrity of the BDN system is critical.

FONAR as exception evidence

The FONAR provides exception evidence specifically for sulphur cap non-compliance. It does not affect BDN integrity (the BDN still records the actual fuel delivered, which may be non-compliant) but provides legal cover for the use of non-compliant fuel during the period of demonstrated non-availability.

Verification and audit

For vessels subject to FuelEU Maritime, the BDN data and any FONAR claims are subject to independent verification by an EU-recognised verifier (typically the same verifier that audits the EU MRV report). The verifier reviews:

  • BDN consistency with engineering logs and noon reports.
  • BDN-to-tank traceability.
  • Sample availability and chain of custody.
  • FONAR documentation completeness (where applicable).
  • WtW intensity certification and ISCC EU traceability (where applicable).

For vessels subject to IMO Net-Zero Framework GFI, the verification framework is being established under MEPC.391 and is expected to broadly mirror the FuelEU framework.

Class society role

Classification societies (DNV, Lloyd’s Register, ABS, BV, NK, KR, RINA, CCS) increasingly perform BDN and FONAR-related verification services for owners and charterers. Class society approval of bunker suppliers and bunker delivery procedures provides assurance that the BDN and FONAR systems are operating reliably.

Practical implementation

Vessel-side procedures

A vessel’s standard bunker procedure should include:

  1. Pre-bunker planning: confirm compliant fuel availability at planned bunker port; if not available, follow FONAR procedure.
  2. Pre-bunker briefing: confirm BDN preparation, sample bottles, meter calibration, communication with supplier.
  3. Bunker transfer monitoring: continuous monitoring of bunker quantity (mass flow meter or tank dipping), sample drawing at start, middle and end of transfer.
  4. BDN review: chief engineer reviews BDN for completeness, signs and retains copy.
  5. Sample sealing: samples sealed in presence of supplier representative, seal numbers recorded.
  6. Tank entry: BDN data entered in vessel’s bunker management system.
  7. PSC preparation: BDN filed in chronological order with samples; quick retrieval for any inspection.

Owner-side procedures

The owner’s bunker management system should:

  • Track BDN data across the entire fleet for compliance reporting and trend analysis.
  • Monitor for off-spec deliveries and trigger insurance claims and supplier disputes as needed.
  • Retain BDNs and samples for the required three-year period (sometimes longer for legal proceedings).
  • Integrate with EU MRV, FuelEU and IMO DCS reporting systems.
  • Maintain FONAR documentation library for use in defending future FONAR submissions.

Charterer interaction

Under time charter contracts, the charterer typically supplies the fuel (the charterer’s responsibility under standard NYPE 2015 terms). The BDN evidences the charterer’s bunker selection and is the basis for any owner-charterer dispute about fuel quality.

The BIMCO BDN Clauses (under development) provide a standard framework for owner-charterer responsibilities around BDN data integrity.

Bunker supplier-side procedures

Bunker suppliers must:

  • Provide accurate BDN data conforming to MARPOL Annex VI and any applicable additional requirements (FuelEU, ISO 8217, port-specific).
  • Maintain ISO 8217-compliant fuel quality.
  • Respond to dispute claims within reasonable timescales.
  • Retain bunker delivery records for the regulatory retention period (typically three to five years).

The principal bunker suppliers maintain ISO 9001 quality management systems and increasingly ISO 14001 environmental management systems.

Future developments

Electronic BDN rollout

The expected commercial rollout of electronic BDN from 2025 to 2027 (Singapore, Rotterdam, ARA, Hong Kong, Hamburg, Long Beach) will significantly streamline the BDN administration. Integration with vessel-side bunker management systems will enable real-time data flow into the FuelEU Maritime and IMO Net-Zero Framework reporting systems.

Mass flow meter mandate expansion

The Singapore MFM mandate (2017) is being replicated in Rotterdam (rolling out 2024), Hong Kong (under consideration), and other major bunker ports. The MFM provides mass-based bunker measurement that is more accurate than the historic dipping-based volumetric measurement.

FuelEU and IMO Net-Zero Framework BDN integration

The FuelEU Maritime BDN extensions (WtW intensity, RFNBO certification) entered force January 2025. The IMO Net-Zero Framework BDN extensions are expected to enter force from 2027. The two frameworks are designed for compatibility but require careful BDN structuring to support both.

FONAR phase-out (potential)

As the global compliant fuel supply chain matures, the FONAR mechanism may become progressively less needed. Some industry observers anticipate a gradual phase-out of FONAR by approximately 2030, replaced by routine port-side compliance monitoring without need for non-availability defence. This is a long-term outlook; FONAR remains operationally important in 2024 to 2025.

Bunker dispute resolution platform

Several bunker industry associations (IBIA, Bunkernet) are developing standardised bunker dispute resolution platforms that integrate BDN data, sample testing, arbitration framework and insurance claim processing. Commercial deployment is expected from 2025 to 2026.

See also

Marine fuels

Regulatory frameworks

Voluntary frameworks and contracts

Operational and technical efficiency

Conventions, codes and class

Ship types

Engines and exhaust

Calculators

References

  • IMO Resolution MEPC.328(76): 2021 Revised MARPOL Annex VI. International Maritime Organization, 2021.
  • IMO MEPC.1/Circ.792: Standard format for the Bunker Delivery Note. International Maritime Organization, 2012 (with updates).
  • IMO MEPC.1/Circ.864 (succeeded by Circ.881): Guidance on the development of a Standardized Format for Reporting Fuel Oil Non-Availability under MARPOL Annex VI Regulation 18.2. International Maritime Organization, 2018 / 2019 / 2020.
  • IMO MEPC.1/Circ.880: Guidance for port State control on contingency measures for addressing non-compliant fuel oil. International Maritime Organization, 2019.
  • IMO Resolution MEPC.182(59) and MEPC.96(47): Guidelines for the sampling of fuel oil for determination of compliance. International Maritime Organization, 2009/2002.
  • ISO 8217:2017 Petroleum products: Fuels (class F): Specifications of marine fuels. International Organization for Standardization, 2017.
  • IBIA. Bunker Industry Code of Practice. International Bunker Industry Association, 2023.
  • Singapore Maritime and Port Authority. Mass Flow Meter Bunker Delivery Procedure. MPA Singapore, 2017.
  • DNV. Maritime Forecast to 2050. DNV Energy Transition Outlook, 2023.
  • Regulation (EU) 2023/1805 of the European Parliament and of the Council of 13 September 2023 on the use of renewable and low-carbon fuels in maritime transport (FuelEU Maritime). Official Journal of the EU, 2023.

Further reading

  • BIMCO. BIMCO Bunker Quality Clause and BIMCO BDN Clauses. BIMCO, 2023 to 2024.
  • ICS. Catalysing the Fourth Propulsion Revolution. International Chamber of Shipping, 2022.
  • IBIA. Annual Bunker Industry Outlook. International Bunker Industry Association, 2024.