FONAR and BDN: Sulphur Compliance Evidence at PSC

The bunker delivery note (BDN) and the fuel oil non-availability report (FONAR) are the two documents a ship holds under MARPOL Annex VI Regulation 18 to evidence compliance with the Regulation 14 sulphur limits. The BDN records the sulphur content of each delivery, and the FONAR records why compliant fuel could not be bought. Neither excuses non-compliance: appendix 1 to IMO Resolution MEPC.320(74) states that a FONAR “is not an exemption”, and a BDN declaration is evidence against the supplier, not a defence for the ship.

A port State control officer reads these documents together with the MARPOL delivered sample, the in-use and onboard samples, and the fuel changeover record. This article sets out what each item proves, how the Appendix VI verification procedure judges a sample, the inspection sequence in MEPC.321(74), and where the FONAR fits. It also covers the regional overlays in the EU, the US and Singapore, and how charter parties and bunker contracts allocate the risk. The regulation itself is covered paragraph by paragraph in MARPOL Annex VI Regulation 18 , and the document as a commercial instrument in the bunker delivery note .

The table is a Shipping-Wiki.com construction from the instruments named in it, not an IMO table.

The sulphur compliance evidence file under Regulations 14 and 18

MARPOL Annex VI splits the sulphur regime between two regulations. Regulation 14 sets the limit and says where it applies. Regulation 18 sets out how compliant fuel is made available, documented and sampled. The operative text of both is the 2021 revised Annex VI adopted by IMO resolution MEPC.328(76) on 17 June 2021, in force 1 November 2022, as amended by MEPC.385(81) from 1 August 2025.

Regulation 14 sets the limit

Regulation 14.1 states that the sulphur content of fuel oil “used or carried for use” on board shall not exceed 0.50% m/m. The limit took effect on 1 January 2020, the date the Committee confirmed by decision MEPC.280(70) on 28 October 2016. The words “or carried for use” were inserted by MEPC.305(73), adopted 26 October 2018 and in force 1 March 2020, and they are the carriage ban . There is no separate paragraph 14.1.3 for the ban; it sits inside paragraph 14.1 itself.

Regulation 14.4 sets 0.10% m/m inside an emission control area . Regulation 14.6 requires a written changeover procedure and a record of the volume of low-sulphur fuel in each tank, with the date, time and position of the changeover, in the logbook or electronic record book the Administration prescribes. Regulation 14.7 gives a 12-month grace period after any new ECA enters into force, during which 14.4 and 14.6 do not apply there.

A ship with an approved exhaust gas cleaning system complies through Regulation 4 equivalent arrangements rather than through the fuel. It may lawfully receive and carry fuel above 0.50% for use in the approved system, which is why the BDN declaration has a third box.

The SOx emission control areas and their dates

Eight SOx ECAs are listed in Regulation 14.3. Seven are in force on 23 September 2026, and the North-East Atlantic ECA is adopted and not yet in force.

The 1 March 2027 and 1 September 2028 dates follow from the Regulation 14.7 grace period, not from text in the designating resolutions. The Mediterranean ECA is a SOx and particulate matter ECA only, not a NOx ECA.

Regulation 18 sets the proof

Regulation 18 carries every documentary duty in the file. The paragraph map below uses the MEPC.328(76) numbering as amended by MEPC.385(81).

Annex VI has no bunker record book and no oil record book. The Oil Record Book is MARPOL Annex I Regulation 17. The sulphur record on board is the changeover log under Regulation 14.6, the NOx tier record under Regulation 13 , and the BDNs themselves.

What the bunker delivery note records and proves

The BDN is the supplier’s certified statement of what it delivered, required by Regulation 18.5.1 for every ship subject to the survey and certification rules of Regulations 5 and 6. The unified interpretation in MEPC.1/Circ.795/Rev.8 paragraph 12.1 applies Regulations 18.5 and 18.6 to all ships of 400 GT and above, and to smaller ships at the Administration’s discretion. The survey itself underpins the IAPP certificate .

The ten Appendix V items

Appendix V of MARPOL Annex VI lists the minimum content, and there is no IMO standard BDN form beyond it.

1. Name and IMO number of the receiving ship.
2. Port.
3. Date of commencement of delivery.
4. Name, address and telephone number of the marine fuel oil supplier.
5. Product name(s).
6. Quantity in metric tonnes.
7. Density at 15 degrees C (kg/m3).
8. Sulphur content (% m/m).
9. The flashpoint (degrees C) specified in accordance with standards acceptable to the Organization, or a statement that the flashpoint has been measured at or above 70 degrees C.
10. The supplier’s signed and certified declaration.

Item 9 was added by MEPC.362(79), adopted 16 December 2022 and in force 1 May 2024, with a footnote to ISO 2719:2016, Procedure A for distillates and Procedure B for residual fuels. A BDN number and the sample seal numbers are not Appendix V items. They are good practice, recommended for seals in paragraph 11.6 of MEPC.1/Circ.875/Add.1, and many contracts require them.

The supplier’s declaration and its three boxes

Item 10 is the supplier’s certification that the fuel conforms to Regulation 18.3 and that its sulphur content does not exceed one of three values. The supplier ticks the Regulation 14.1 limit, the Regulation 14.4 limit, or a purchaser-specified limit. The third box applies only where the purchaser has notified that the fuel will be used with a Regulation 4 equivalent, or under a trial exemption under Regulation 3.2.

The tick-box form came from MEPC.286(71), adopted 7 July 2017 and in force 1 January 2019. A BDN for high-sulphur fuel oil with the third box ticked is a lawful document for a scrubber ship. The same document on a ship without an approved system is evidence of a carriage ban breach.

Low-flashpoint and gas fuels since 1 August 2025

MEPC.385(81), adopted 22 March 2024 and in force 1 August 2025, split the BDN rule. Regulation 18.5.2 applies to a low-flashpoint fuel or a gas fuel such as LNG or methanol . That BDN carries Appendix V items 1 to 6, the density measured by a method suited to the fuel with its temperature, and a signed supplier declaration of conformity with Regulation 18.3.

The sulphur content is given as a tested value or, with the agreement of the port of supply authority, as a statement that it is below 0.001% m/m. The amendment narrowed Regulation 18.4 so that only paragraphs 5.1, 8.1 and 8.2 are disapplied for these fuels. Retention under 18.6, inspection under 18.7 and the supplier undertakings under 18.9 now apply to an LNG or methanol BDN. The IGF Code governs the fuel system itself.

The SOLAS flashpoint declaration since 1 January 2026

MSC.520(106), adopted 10 November 2022 and in force 1 January 2026, added a parallel duty in SOLAS chapter II-2 . Regulation II-2/4.2.1.6 requires ships carrying oil fuel to be given, before bunkering, a declaration signed by the supplier’s representative that the fuel conforms to the flashpoint rule, naming the test method. The BDN must contain the flashpoint or a statement that it was measured at or above 70 degrees C.

New SOLAS regulation II-2/3.59 defines a confirmed case as a representative sample, analyzed by an accredited laboratory, showing a flashpoint below 60 degrees C. Governments report confirmed cases to IMO under 4.2.1.7. The flashpoint entry is therefore both a MARPOL Appendix V item and a SOLAS obligation.

Electronic BDNs

MEPC 80 approved a unified interpretation, issued as MEPC.1/Circ.795/Rev.8 of 24 July 2023, accepting a BDN “in either hard copy or electronic format”. An electronic BDN must carry the Appendix V information and be retained under 18.6. It should also be protected from edits and authenticable by a method such as a tracking number, watermark, date and time stamp, QR code or GPS coordinates. Singapore made the e-BDN its default from 1 April 2025.

Retention and inspection

Regulation 18.6 requires the BDN to be kept on board, readily available for inspection at all reasonable times, for three years after delivery. The clock runs from delivery, not from consumption. Regulation 18.7.1 lets the competent authority inspect the notes, copy them, require the master to certify a true copy, and verify the contents with the port where the note was issued. Regulation 18.7.2 requires this to be done as expeditiously as possible without causing the ship to be unduly delayed.

A ship of 400 GT and above on a scheduled service with frequent and regular port calls may, under Regulation 18.11, have compliance with 18.6 documented in an alternative manner the Administration approves after consulting affected States.

What the BDN does not prove

The BDN proves what the supplier certified. It does not prove what was delivered, which is the job of the MARPOL delivered sample, and it does not prove what the ship burned. Under clause 6(c) of BIMCO Bunker Terms 2018, the master’s signature on the BDN acknowledges “the actual volume and the actual delivery temperature only”. The same clause says the sulphur figure on the note is determined by ISO 8754, not verified by the ship.

A BDN at 0.48% against a delivered sample that tests at 0.52% is two pieces of evidence in conflict. Appendix VI Part 1 compares the sample result to the Regulation 14 limit, not to the BDN, so the fuel has not met the requirement. The BDN then becomes the evidence against the supplier under Regulation 18.9.4, which requires Parties to act against suppliers found to deliver fuel that does not match the note.

The MARPOL delivered sample and the commercial samples

The MARPOL delivered sample , defined at Regulation 2.1.22, is the only sample MARPOL requires to accompany the BDN. Regulation 18.8.1 requires it to be taken “taking into account the guidelines developed by the Organization”. It must be sealed and signed by the supplier’s representative and the master or officer in charge on completion of bunkering. The ship keeps it under its control until the fuel is substantially consumed, and in any case for not less than 12 months.

Volume, location and sealing under MSC-MEPC.2/Circ.18

The guidelines are now MSC-MEPC.2/Circ.18 of 11 July 2024, approved by MEPC 81 and MSC 108, which revoked MEPC.182(59) of 2009. Paragraph 6.1 places the sampling point at the receiving ship’s inlet bunker manifold, with the sample drawn continuously throughout the delivery. Paragraph 7.3 sets a container volume of not less than 600 ml, filled to 90% plus or minus 5% and sealed. The 400 ml figure in MEPC.182(59) is out of date, and so is any procedure still written to it.

The joint MSC-MEPC circular covers both the MARPOL sulphur check and the SOLAS flashpoint check. A delivered sample whose seal has been broken before it reaches the laboratory is rejected under Appendix VI paragraph 2.2.3, so seal integrity is the whole value of the sample.

Commercial samples under the supply contract

Commercial samples are separate from the MARPOL sample and are governed by contract. The June 2018 BIMCO and IBIA Bunkering Guide says they “are not interchangeable once sealed”. Clause 4 of BIMCO Bunker Terms 2018 divides the primary sample into at least five identical samples, with one kept on board for MARPOL purposes. The sellers retain two for a minimum of 45 days after delivery. The BIMCO Bunkering Operations and Sampling Clause 2011 for time charters calls for at least seven, two each for owners, charterers and suppliers plus the MARPOL sample.

Paragraph 9.15 of MEPC.1/Circ.875/Add.1 recommends suppliers keep their commercial samples for a minimum of 30 days, longer if disputed. These are the samples that decide a bunker quality dispute between buyer and seller over the nominated ISO 8217 grade . The MARPOL sample decides the regulatory question. Both 2011 BIMCO clauses and the Bunker Terms still name MEPC.182(59), with Bunker Terms adding “or any subsequent amendments”.

Seal numbers on the BDN

No IMO regulation requires seal numbers on the BDN. Paragraph 11.6 of MEPC.1/Circ.875/Add.1 recommends it, and paragraph 9.6 recommends that sealing be witnessed by both parties with unique seal numbers recorded and countersigned. Where the supplier refuses to take the sample at the ship’s manifold, or refuses to enter the ship’s seal numbers, P&I guidance recommends a letter of protest. Gard (12 May 2021) and Steamship Mutual (26 October 2022) both give that advice.

In-use and onboard samples and the Appendix VI verification procedure

The in-use and onboard samples are drawn by or for the competent authority to check what a ship burns and what it carries, and Appendix VI decides whether the result has met the limit. MEPC.324(75), adopted 20 November 2020 and in force 1 April 2022, added both samples to the Annex and replaced Appendix VI in full.

Sampling points under Regulations 14.8 to 14.13

Regulation 14.8 provides for the in-use sample, taken from a designated sampling point in the service line, and the onboard sample, taken from a tank. Ships built before 1 April 2022 had to fit the in-use sampling point by the first renewal survey on or after 1 April 2023. Regulation 14.12, as amended by MEPC.385(81), does not require a sampling point on a low-flashpoint or gas fuel service system.

MEPC.1/Circ.864/Rev.1 of 21 May 2019 gives the in-use sampling guidance, including seven conditions for the sampling point location and sealing by the inspector. It revoked the original MEPC.1/Circ.864 of 9 December 2016. MEPC.1/Circ.889 of 7 December 2020 covers the onboard sample from tanks, which is how a port State proves fuel is carried for use in breach of the carriage ban.

Part 1: the delivered sample has no test margin

Part 1 of Appendix VI verifies the MARPOL delivered sample. The laboratory splits it into two subsamples and averages the results as X. If X is equal to or less than the Regulation 14 limit, the fuel “shall be considered to have met the requirement”. If X is greater, it has not. Table 1 carries no test margin. A delivered sample at 0.51% against a 0.50% limit fails.

Part 2: in-use and onboard samples and the 0.59R margin

Part 2 verifies in-use and onboard samples. The averaged result Z is compared to the limit V plus 0.59R, where R is the reproducibility of the test method. Paragraph 4.5.2 states that a result above V but at or below that margin “shall be considered to have met the requirement”. Above the margin, it has not, and paragraph 4.6 says the final results “shall be evaluated by the competent authority”.

Results are reported to two decimal places. The margins are exact tabulated values, not approximations, and there is no re-test step between 0.50% and 0.53%. An in-use result of 0.52% has met the 0.50% requirement, and a delivered result of 0.52% on the same parcel has not. The two sample types can give opposite answers on the same fuel.

The margins are often attributed to MEPC.1/Circ.864 or described as a 95% confidence level. Neither is correct. The figures come from Appendix VI Table 2, MEPC.1/Circ.864 dealt with sampling points and was revoked in 2019, and no IMO text on the procedure uses the words “95%” or “confidence”.

Laboratory and test method

The Appendix VI procedure, and paragraph 4.1.2 of MEPC.320(74), name ISO 8754:2003, the energy-dispersive X-ray fluorescence method. The test is run by a laboratory accredited to ISO/IEC 17025:2017 or equivalent. ISO 8754:2025 has since replaced the 2003 edition, while the IMO texts still name 2003. ISO 8217:2024 lists ISO 8754, ISO 14596:2007 and ASTM D4294 as the sulphur methods for commercial specification. The precision rules of ISO 4259 govern commercial disputes but not the Appendix VI regulatory margin.

The port State control sulphur inspection sequence

Port State control of sulphur compliance follows MEPC.321(74), the 2019 Guidelines for port State control under MARPOL Annex VI Chapter 3, adopted 17 May 2019. The inspection starts with documents and moves to sampling only on clear grounds.

Initial inspection: documents checked

1. The IAPP certificate and its supplement, including any Regulation 4 equivalent and its approval.
2. The BDNs for the last three years, checked against Appendix V, with the MARPOL delivered samples that match them.
3. The Regulation 14.6 changeover procedure and log entries for each ECA entry and exit.
4. Any notification the master has made under MEPC.321(74) paragraphs 2.1.5 or 2.1.6 about a defective BDN, a missing sample or an off-spec delivery.
5. Any FONAR submitted, with its attachments.
6. On a scrubber ship, the EGCS records and any EGCS record book the approval requires.

The ship implementation plan under MEPC.1/Circ.878 is not on the list as a requirement. Paragraph 4 of that circular states that a plan “is not a mandatory requirement”.

Clear grounds and sampling

Findings in the file that lead an inspector to sample include a BDN missing an Appendix V item, a sulphur figure above the applicable limit on a ship without an equivalent, a missing or broken-seal delivered sample, and a changeover log that does not reconcile with the ECA boundary. The inspector may then take an in-use sample from the designated point, an onboard sample from a tank, or send the MARPOL delivered sample for analysis. Regulation 18.7.2 requires this to be done without undue delay to the ship.

Reconciling the file

The officer’s task is to reconcile documents that were produced by different parties at different times. The matrix below is a Shipping-Wiki.com construction from Regulations 14 and 18, Appendix VI and MEPC.321(74), not an IMO table.

Deficiency codes

The Paris MoU deficiency code list of 1 July 2023 records sulphur findings under group 146. Code 14604 is bunker delivery notes, 14607 quality of fuel oil, 14612 SOx records, 14615 the fuel changeover procedure, 14616 alternative arrangements (SOx) and 14617 sulphur content of fuel used. The Paris MoU and Tokyo MoU publish their own code lists; the PSC deficiency codes article explains the group structure.

The FONAR in the evidence file

A FONAR is the notification a ship makes under Regulation 18.2.4 when it cannot buy compliant fuel oil, supported by the evidence Regulation 18.2.1 describes. The full procedure is in the fuel oil non-availability report article. This section covers what the port State reads when a FONAR sits in the file.

Legal basis: Regulation 18.2.1 to 18.2.5

Regulation 18.2 has five paragraphs, and each assigns a different duty.

• 18.2.1. If a Party finds a ship not in compliance, it “is entitled to require the ship to” present a record of the actions taken to achieve compliance. It may also require evidence that the ship tried to buy compliant fuel in line with its voyage plan, looked for alternative sources where it was not available, and found none “despite best efforts”.
• 18.2.2. “The ship should not be required to deviate from its intended voyage or to delay unduly the voyage in order to achieve compliance.”
• 18.2.3. The Party “shall take into account all relevant circumstances and the evidence presented to determine the appropriate action to take, including not taking control measures”.
• 18.2.4. “A ship shall notify its Administration and the competent authority of the relevant port of destination when it cannot purchase compliant fuel oil.”
• 18.2.5. The Party notifies IMO when a ship has presented evidence of non-availability.

The regulation does not say the FONAR shifts a burden of proof in either direction. It gives the Party a right to require evidence and an obligation to weigh it.

The standard format: appendix 1 to MEPC.320(74)

The standard FONAR format is appendix 1 to MEPC.320(74), the 2019 Guidelines for consistent implementation of the 0.50% sulphur limit, adopted 17 May 2019. Paragraph 5.2 of the guidelines sets it out pursuant to Regulation 18.2.4. It has eight sections.

The form has no field for call sign, gross tonnage, deadweight or EGCS type. MEPC.1/Circ.878, often cited as the FONAR format, is the ship implementation plan guidance of 9 November 2018. Its only FONAR content is appendix 1 item 6.4: the ship “should have a procedure for Fuel Oil Non-Availability Reporting (FONAR)”. Several flags, including the Marshall Islands with form MI-112 under Marine Notice 2-013-8, issue their own versions built on the IMO appendix.

Timing, recipients and retention

Note 1 of the format asks for the FONAR to be sent “as soon as it is determined that the ship/operator will be unable to procure compliant fuel oil and preferably before the ship leaves the port/terminal where compliant fuel cannot be obtained”. Paragraph 5.1.4 of MEPC.320(74) names the port State Administration in the port of arrival and the flag Administration. The same note says a copy “should be kept on board for inspection for at least 36 months”. That period is guidance in a non-mandatory resolution, not a Regulation 18 obligation, but flags repeat it and inspectors ask for it.

Regulation 18.2.4 does not define the relevant port of destination where a ship will call at several ports in one ECA. Filing with each national authority on the route is the conservative practice.

What counts as genuine non-availability

Section 3 of the form and the appendix to MEPC.321(74) set the evidence standard. The PSC guidelines list what the port State may consider, and item .4 states that “the cost of compliant fuel is not considered to be a valid basis for claiming non-availability of fuel”. Price is not a defence, and neither is a charterer’s decision not to buy.

Note 3.3 of the format expects the ship to consider logistics such as changing berth or anchoring within a port or terminal to obtain compliant fuel. Regulation 18.2.2 says the ship should not be required to deviate from its voyage. The text draws no line between a berth shift inside the bunker port, which is expected, and a diversion to another port, which is not required.

Note 3.2 says that for insufficiently supported or repeated claims the Party may require more documentation. The ship or operator may also be subject to more extensive inspections in port, and section 7 of the form puts the ship’s FONAR history in front of the inspector.

What a port State may do after a FONAR

MEPC.1/Circ.881 of 21 May 2019 is the IMO guidance for port State control on contingency measures for non-compliant fuel oil. Paragraph 1 lists four options:

1. the actions in the ship implementation plan under MEPC.1/Circ.878;
2. discharging the non-compliant fuel “to another ship to be carried as cargo or to an appropriate shipboard or land-based facility”;
3. management by another method acceptable to the port State;
4. operational actions, including retention of the non-compliant fuel on board.

Paragraph 2 says the fuel “may be discharged to the port or retained on board, as acceptable to the port State”. Paragraph 3 asks the port State, the flag State and the ship to work together on a solution, taking the FONAR into account, and paragraph 4 covers flushing and dilution after discharge. The circular says nothing about who pays, sets no penalty, and does not rank the delivered sample above an in-use result. De-bunkering non-compliant fuel is one outcome of that process, not an automatic consequence of a FONAR.

FONAR, the carriage ban and scrubber ships

The carriage ban in Regulation 14.1 has no FONAR exception written into it. A ship without an approved equivalent that has non-compliant fuel on board after a FONAR relies on the port State accepting one of the Circ.881 options, including retention on board. A ship with an approved EGCS has no need of a FONAR for fuel used through the system. It may need one if it must run a consumer outside the system on fuel above the limit, and MEPC.1/Circ.883 covers scrubber failure separately.

How many FONARs are filed

Regulation 18.2.5 notifications go into the GISIS MARPOL Annex VI module , which paragraph 5.1.8 of MEPC.320(74) names as the platform. In a press briefing on 28 January 2021, IMO reported that 55 cases of 0.50% compliant fuel being unavailable had been recorded in GISIS through 2020. Separately, MEPC.1/Circ.880 of 9 November 2018 invites Parties to report fuel availability under Regulation 18.1 through the same module.

Defective BDNs and off-spec deliveries

When compliant fuel was bought and something went wrong at delivery, the ship’s record is a supplier notification, not a FONAR. MEPC.321(74) recognizes two routes.

• Paragraph 2.1.5. Where the BDN or the sample does not meet the requirements, the master or officer in charge may document it in a notification to the flag Administration. Copies go to the port authority where the ship did not receive proper documentation and to the bunker deliverer.
• Paragraph 2.1.6. Where the BDN shows compliant fuel but the master holds independent test results of the ship’s own bunkering sample showing non-compliance, the notification goes to the flag, the destination port authority, the supplier’s Administration and the supplier.

Paragraph 2.1.7 says a copy may be retained on board in either case. Flag rules can go further: Marine Notice 2-013-8 of the Marshall Islands, revision of September 2025, section 3.7.4, requires the details to be recorded in the ship’s log and notified to the Administrator. That applies where a BDN or sample is not provided, or where the fuel does not match the BDN.

A letter of protest to the supplier’s representative is the contractual counterpart. Clause 6 of BIMCO Bunker Terms 2018 provides for remarks on the BDN or a separate letter of protest where the buyer is not satisfied with sampling, quantity or any other matter. The June 2018 BIMCO and IBIA guide advises against signing the BDN until the note is correct and a copy of the protest has been receipted. Britannia P&I (9 October 2024) goes further and advises not signing the BDN where concerns remain. Those are practice positions, not law, and they differ.

The port State’s duties then run to the supplier. Regulation 18.10.1 requires Parties to inform the Party under whose jurisdiction the BDN was issued. Regulation 18.9.4 requires action against suppliers delivering fuel that does not match the note, and 18.9.6 requires supplier failures to be reported to IMO. Where a ship is left holding fuel it cannot legally use, the Circ.881 options apply. The commercial side runs through off-spec bunkers under a time charter .

Regional overlays on the IMO baseline

The IMO instruments are the baseline everywhere Annex VI applies. The EU, the US and Singapore add rules that change what the file must contain in their waters and ports.

European Union

Directive (EU) 2016/802 of 11 May 2016 transposes the Annex VI sulphur rules for EU waters and adds a berth limit. Article 7(1) caps fuel used by ships at berth in Union ports at 0.10% by mass. The crew is given time to change over as soon as possible after arrival and as late as possible before departure, with the time recorded in the logbook. Article 7(2) exempts ships due at berth for less than two hours according to published timetables, and ships that switch off all engines and use shore-side electricity .

Article 6(8) mirrors Regulation 18.2. A Member State may require the record of actions and evidence of attempts to purchase, the ship “shall not be required to deviate”, and the ship notifies its flag State and the destination port authority. The port State notifies the Commission. Article 6(9) requires a publicly available register of local suppliers, and a BDN “accompanied by a sealed sample signed by the representative of the receiving ship”. Article 6(6) requires ships’ logbooks, including changeover operations, to be completed correctly.

Commission Implementing Decision (EU) 2015/253 of 16 February 2015 sets the inspection floor. Article 3(1) requires logbook and BDN inspection on at least 10% of individual ships calling. Article 3(2) requires sampling on 40% of inspected ships in States fully bordering a SECA, 30% partly bordering, and 20% not bordering, rising to 30% from 1 January 2020. Article 7(c) requires annual reporting of non-availability claims, including the bunkering port, the number of claims by the same ship and the fuel type unavailable. Article 18 of the Directive requires penalties that are “effective, proportionate and dissuasive”.

Article 13(2) of the Directive still refers to sampling under MEPC.182(59), which IMO revoked on 11 July 2024.

United States

40 CFR Part 1043 implements Annex VI in US law. Section 1043.80 requires suppliers to provide BDNs for fuel delivered to vessels of 400 GT and above voyaging to ports or offshore terminals under the jurisdiction of other Parties. The listed contents include the fuel type and designation under 40 CFR part 1090 and the sulfur content in weight percent. The supplier’s statement “is deemed to be a submission to EPA”. Section 1043.70(a) requires owners and operators to keep records including BDNs.

The FONAR route changed in 2019. The US EPA states that from 28 June 2019 a ship unable to purchase compliant fuel satisfies Regulation 18.2.4 by notifying the cognizant US Coast Guard Captain of the Port. EPA stopped accepting FONARs and closed its FOND portal on 30 June 2019. The North American and US Caribbean ECAs are enforced under that framework.

Singapore, Rotterdam and Antwerp-Bruges

The Maritime and Port Authority of Singapore made the electronic BDN the default from 1 April 2025, using MPA-whitelisted digital bunkering solutions. The e-BDN can be verified through the e-BDN record enquiry system on digitalPORT@SG, and SS 709:2024 specifies the digital documentation. Port Marine Circular No. 12 of 2024, dated 1 November 2024, mandated SS 648:2024 for mass flow meter custody transfer to ocean-going ships from 1 April 2025.

The ports of Rotterdam and Antwerp-Bruges made mass flow meters mandatory on bunker vessels supplying residual fuel, distillates and biofuels from 1 January 2026, following ISO 22192:2021 except where European rules differ. A metered e-BDN narrows quantity disputes. It does not change the sulphur verification rules, which still rest on the MARPOL delivered sample and Appendix VI.

Contractual allocation of sulphur risk

Regulation 14 binds the ship and Regulation 18.9 binds the supplier through its State. The charter party and the supply contract decide who pays when the documents show a problem. On a time charter the charterer buys the fuel, so the owner’s compliance depends on paperwork the owner does not control.

Time charter clauses

The explanatory notes to the BIMCO 2020 sulphur clause read “related requirements” as covering documents such as the BDN. No current BIMCO or INTERTANKO clause mentions FONAR. The UK P&I Club (24 June 2019) wrote that the clauses were drafted before the IMO FONAR guidelines. It recommended express wording on best efforts, FONAR preparation and deviation, because owners on time charter are “entirely dependent on charterers to provide the paper trail”. The 2020 Fuel Transition Clause was written for the transition and does not by its terms govern a later de-bunkering ordered under Circ.881. Standard forms such as NYPE 2015 are commonly amended with these clauses, and the fuel on board at each end is dealt with under bunkers on delivery and redelivery .

The bunker supply contract

BIMCO Bunker Terms 2018 is the standard seller and buyer contract. Clause 4 governs sampling, with at least five samples and two retained by sellers for 45 days. Clause 6(c) limits the master’s BDN signature to volume and temperature, and clause 9(a)(i) requires a quantity dispute to be noted at delivery and claimed within 14 days. Clause 9(b)(i) requires a quality claim to be notified within 30 days of delivery, unless the Election Sheet provides otherwise. Clause 15 caps sellers’ liability at the invoice value or USD 500,000, whichever is higher. The deadlines run from delivery, and a MARPOL sample result can arrive after them, so the ship’s own commercial sample should be tested promptly.

Disputes under these forms go to arbitration, usually under the LMAA, SMA or SCMA rules , and the FONAR, BDN and protest letters are the documentary record. Liability that escapes the contract chain can fall on the owner’s P&I club for fines, subject to club rules.

BDN data beyond sulphur

The BDN quantity is also the input to carbon reporting, so an error in it carries into several filings at once. The IMO Data Collection System under Regulation 27 of Annex VI and the EU MRV Regulation both accept BDNs as a fuel consumption method. FuelEU Maritime , Regulation (EU) 2023/1805, in force 12 October 2023 and applicable from 1 January 2025, builds its GHG intensity calculation on the fuel quantities and types reported. The CII rating under Regulation 28 of Annex VI, for ships of 5,000 GT and above, uses the DCS fuel data.

None of these schemes has a Regulation 18.2 equivalent for its own limits. The IMO Net-Zero Framework was approved at MEPC 83 in April 2025, and its adoption was adjourned in October 2025, so it has no non-availability provision in force.

BDN and FONAR compared

Shipboard procedure for keeping the file inspection-ready

The ISM Code safety management system is where a company fixes these steps. The list below is drawn from Regulation 18, MSC-MEPC.2/Circ.18, MEPC.321(74) and the flag and industry guidance named above.

1. Before bunkering, obtain the supplier’s pre-delivery documentation under the transfer procedures of ISO 13739:2020 . From 1 January 2026, this includes the SOLAS II-2/4.2.1.6 flashpoint declaration.
2. Agree the sampling point at the ship’s inlet manifold and witness the continuous drip sample for the whole delivery. Record any disagreement in a letter of protest.
3. Seal the MARPOL delivered sample in a container of at least 600 ml, record the seal numbers, and have the supplier’s representative and the officer in charge sign the label.
4. Check the BDN against the ten Appendix V items, or the 18.5.2 content for LNG or methanol, before signing. Check which declaration box is ticked against the ship’s equivalent status.
5. File the BDN and log the sample. Keep the BDN three years and the sample until the fuel is substantially consumed and at least 12 months.
6. Send a commercial sample for testing promptly, inside the contract’s claim periods.
7. If the result or the documents are defective, notify under MEPC.321(74) paragraph 2.1.5 or 2.1.6, make the log entry the flag requires, and protest to the supplier.
8. Before entering an ECA, complete the Regulation 14.6 changeover and log the volumes, date, time and position, following fuel switching operations practice.
9. If compliant fuel cannot be bought, prepare the FONAR on the MEPC.320(74) format as soon as that is known, send it to the flag and the destination authority, and keep a copy on board for at least 36 months.

Tank segregation in the fuel oil system decides whether a non-compliant parcel can be isolated and retained under a Circ.881 option. Mixing it into a tank of compliant fuel removes that option.

Limitations

This article states the IMO baseline and the EU, US and Singapore overlays read from their primary texts. China operates domestic emission control areas under national rules, with its own FONAR practice. Those rules are outside the Annex VI instruments and are not described here, and other national rules may add requirements not stated.

Several positions are guidance rather than law. The 36-month FONAR retention is a “should” in MEPC.320(74), and the sampling volume is set by a circular. The seal-number recommendation is in a best-practice circular. The meaning of “substantially consumed”, the “relevant port of destination” on a multi-port ECA call, and the line between a berth shift and a deviation are not defined in the text. Port States may resolve them differently.

The BIMCO Bunker Terms 2018 clause references are to the V1.1 form. Contracts are routinely amended, and the Election Sheet can change the notice periods and the liability cap. Clause positions described here are those of the standard forms, not of any concluded fixture. Nothing here is legal advice on a particular case, and a detention or dispute should be handled with the flag Administration, the P&I club and counsel.

Related Articles

• MARPOL Annex VI Regulation 18: bunker delivery note
• Fuel oil non-availability report
• Bunker delivery note
• MARPOL Annex VI Regulation 14: sulphur cap
• MARPOL Annex VI sulphur cap
• MARPOL delivered sample
• In-use and onboard fuel oil sampling
• Appendix VI verification procedure
• Very low sulphur fuel oil
• Marine gas oil
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• Bunkering operations
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