Maritime carbon accounting · IMO and EU

One voyage.
Three different
carbon numbers.

EU ETS, FuelEU Maritime and the IMO carbon intensity indicator each count the same tonne of fuel a different way. One counts certified biofuel as zero, one counts it well to wake, one counts it only if you carry the paperwork. Meridian Wake prices all three from the same noon report, before the charter is fixed.

Book a walkthrough Read the API docs

Voyage legs priced, 12 months to Jun 2026: 1,341,802
Vessels under management: 2,880
p95 latency, voyage estimate: 118 ms
Uptime, trailing 12 months: 99.97%

Voyage exposure calculator Live engine · v3.14.0

Trade lane

Vessel

Alternative fuel

Compliance year

Energy share on alternative fuel 30%

Sea speed 14.5 kn

EUA price EUR 78 / t

EU ETS

100% surrender

EUR 0

Rated CO₂e in scope0 t
EUAs to surrender0
Voyage scope factor100%

FuelEU

Surplus, poolable

EUR 0

Attained / target0.00 / 89.34
Compliance balance0 t VLSFOeq
Energy in scope0 GJ

IMO CII

Z = 11%

Cratio 1.00

Attained AER0.00
Required CII0.00
Reference linea=4745, c=0.622

Distance0 nm

Duration0.0 d

Bunkers lifted0 t

Bunker costUSD 0

Carbon costUSD 0

Carbon vs bunkers0%

Rated CO₂ excludes ISCC certified biofuel and RFNBO under Directive 2003/87/EC Art. 14 and the MRV regulation. FuelEU counts the same energy at its well to wake default from Annex II. CII counts it under MEPC.1/Circ.905. Voyage basis AER is annualised for the rating and is indicative only. Defaults shown; certified values override.

DIR 2003/87/EC ART. 3GEREG (EU) 2023/1805MEPC.352(78)

The same fuel, counted three ways, by three authorities, on three calendars.

A Panamax lifts 640 tonnes of a B30 UCOME blend in Singapore. Under EU ETS the certified biofuel fraction is zero rated, so the operator surrenders allowances on 70% of the carbon. Under FuelEU the same fraction carries a well to wake intensity of 20.2 gCO₂e per megajoule, which is not zero, and it is the number that decides the compliance balance. Under the IMO carbon intensity indicator it counts only if the bunker delivery note carries a proof of sustainability that satisfies MEPC.1/Circ.905.

Three regimes, three answers, and none of them arrive in the same file. The ETS position lives in the Union Registry. The FuelEU balance lives in the FuelEU database at EMSA. The CII lives in the ship energy efficiency management plan and is verified by the recognised organisation. Most owners reconcile them in a spreadsheet, once a quarter, after the voyage is over and the exposure is already fixed.

Before the fixturePrice the carbon leg of a voyage estimate in the same minute as the freight, not in the quarterly true up.
One ingestNoon reports, bunker delivery notes and AIS reconcile into a single voyage record with a full audit trail.
Verifier readyOutput maps to the EU MRV emissions report, the FuelEU report and the IMO DCS submission without re-keying.

One voyage. Three different measuring sticks.

Rotterdam to Singapore, 8,288 nautical miles. The EU counts half of it because half a voyage that starts in an EU port is inside the perimeter. The IMO counts all of it, because a carbon intensity indicator does not care where the water is.

ENGINE CONSTANTSEDITION 2026.2REVISED 2026-07-09

The constants the engine runs on, published.

Every number below is a regulated default. Where you hold a certified value, an ISO 8217:2024 bunker delivery note or a verified proof of sustainability, the engine uses yours and records which one it used against the voyage.

Fuel constants used by the engine
Fuel	C_F t CO₂/t	LCV MJ/kg	WtW gCO₂e/MJ	ETS rated	Source
HFO / VLSFO 0.50%	3.114	40.5	91.7	Yes	MEPC.364(79) / FuelEU Annex II
MGO / MDO, DMA	3.206	42.7	90.8	Yes	MEPC.364(79) / FuelEU Annex II
LNG, Otto medium speed	2.750	49.1	76.1	Yes	FuelEU Annex II, slip included
Methanol, fossil	1.375	19.9	101.4	Yes	MEPC.364(79)
UCOME, ISCC EU certified	0.000	37.0	20.2	No	RED III Annex VI / MRV Art. 3
e-Methanol, RFNBO	0.000	19.9	5.2	No	Del. Reg. (EU) 2023/1185
Ammonia, blue	0.000	18.6	62.5	No	FuelEU Annex II default

EU ETS phase in

Share of verified emissions for which allowances must be surrendered.

202440%
202570%
2026 onward100%
CH₄ and N₂O added2026
Voyages between an EU and a non-EU port50%
Intra-EU voyages and time at berth100%

Surrender falls to the shipping company, meaning the ISM Company, unless a mandate transfers it. The BIMCO Emission Trading Scheme Allowances Clause 2022 is the usual vehicle for that transfer in a time charter.

FuelEU intensity ladder

Limit on well to wake greenhouse gas intensity, against a 2020 fleet reference of 91.16 gCO₂e/MJ.

2025 to 2029−2% → 89.34
2030 to 2034−6% → 85.69
2035 to 2039−14.5% → 77.94
2040 to 2044−31% → 62.90
2045 to 2049−62% → 34.64
2050 onward−80% → 18.23

Penalty is EUR 2,400 per tonne of VLSFO equivalent energy in deficit, computed as the absolute compliance balance divided by the attained intensity times 41,000. A deficit in consecutive periods multiplies the penalty by 1 + (n − 1)/10.

CII reference lines

Required annual carbon intensity is a × dwt^−c, reduced by the year factor Z.

Bulk carrier, dwt < 279,000a 4745, c 0.622
Tankera 5247, c 0.610
Container shipa 1984, c 0.489
Gas carrier, dwt < 65,000a 8104, c 0.639
Z factor 2023 / 24 / 25 / 265 / 7 / 9 / 11%
Z factor 2027 onwardIndicative

Rating boundaries come from the dd vectors in MEPC.354(78). For a bulk carrier those are 0.86, 0.94, 1.06 and 1.18 times the required value. Z beyond 2026 is not yet set by MEPC and is flagged as indicative wherever it appears in the product.

On the watchlist, not yet in the engine

Constants we hold in staging and ship the day they enter into force.

IMO Net-Zero Framework, Tier 1 remedial unitUSD 100 / t CO₂e
Tier 2 remedial unitUSD 380 / t CO₂e
FuelEU RFNBO sub-target2% from 2034
Onshore power obligation, TEN-T ports2030

We do not price instruments that are not in force. When a framework moves from approval to entry into force we ship the constants inside five business days and version the change in the API.

REG (EU) 2015/757 ART. 12MONITORING PLANTHETIS-MRV

Four data streams, one voyage record, one number that survives an audit.

A verified emissions report is only as good as the reconciliation behind it. The engine cross-checks the mass balance from bunker delivery notes against flow meter totals and AIS derived distance, and flags a voyage the moment they disagree by more than the monitoring plan tolerance.

Noon and event reports

Normalised from 38 owner schemas. Consumption by fuel grade and by consumer, ROB, slip, weather factor, off-hire.

Danelec
StormGeo
Kongsberg Vessel Insight
NAPA Fleet
Hanseaticsoft CFM
Email and CSV drop

Position and distance

Terrestrial and satellite AIS, deduplicated and gap filled. Distance travelled through water reconciled against distance over ground.

Spire Maritime
Kpler
MarineTraffic
Onboard GPS via Inmarsat Fleet Data

Bunkers and sustainability

Bunker delivery notes parsed to ISO 8217:2024 fields, with proof of sustainability matched to the exact stem for biofuel and RFNBO claims.

Integr8 Fuels
KPI OceanConnect
Bunker Metric
ISCC EU certificates
Emerson Coriolis totals

Commercial and technical

Fixtures, laycan, charterparty carbon clauses and the vessel particulars that drive the reference line.

Veson IMOS
Q88
Sea/ (Sea Trade Platform)
DNV Navigator Port
ABS My Digital Fleet
Marcura DA-Desk

Reconciliation tolerances, as shipped

±1.5%BDN mass against flow meter total, per stem. Beyond this the voyage is held for review.
±3.0%AIS derived distance against logged distance over ground.
±0.5%ROB continuity between the close of one voyage and the open of the next.
24 hMaximum gap in AIS coverage before the leg is flagged for manual position entry.

APIVERSION HEADER 2026-05-01OPENAPI 3.1

The engine is an API first. The interface is one client of it.

Date pinned versioning, idempotent writes, cursor pagination, and a sandbox seeded with four vessels and two years of noon reports so you can integrate before the contract is signed.

Selected endpoints

POST/v1/voyages/estimatePrice a voyage before it is fixed
GET/v1/voyages/{voyage_id}Verified position with full audit trail
POST/v1/noon-reports:batchUp to 5,000 reports per call
GET/v1/vessels/{imo}/ciiAttained and required, year to date
GET/v1/fleet/fueleu/balanceCompliance balance across the fleet
POST/v1/fueleu/poolsCreate and settle a compliance pool
GET/v1/ets/positionsEUA requirement against holdings
GET/v1/reference/fuelsConstants, versioned

Webhooks

voyage.priced
cii.rating_changed
fueleu.balance_updated
ets.surrender_due
reconciliation.flagged

Rate limit: 600 req/min per organisation, burst 60/s
Idempotency: Idempotency-Key, 24 h replay window
Auth: OAuth 2.0 client credentials, mTLS optional
Breaking changes: New date version, 18 month support on the old one

Requestcurl

curl -X POST https://api.meridianwake.com/v1/voyages/estimate \
  -H "Authorization: Bearer $MW_TOKEN" \
  -H "Meridian-Version: 2026-05-01" \
  -H "Idempotency-Key: 8b1f-est-0442" \
  -H "Content-Type: application/json" \
  -d '{
    "imo": "9731284",
    "departure_port": "ESALG",
    "arrival_port": "GRPIR",
    "distance_nm": 1617,
    "sea_speed_kn": 14.5,
    "compliance_year": 2026,
    "fuels": [
      { "grade": "VLSFO",  "energy_share": 0.70 },
      { "grade": "LNG_OTTO_MS", "energy_share": 0.30 }
    ],
    "eua_price_eur": 78.00
  }'

Response200 OK · 41 ms

{
  "voyage_id": "vy_01JZQ8K3XN4M",
  "scope": { "basis": "INTRA_EU", "factor": 1.0 },
  "fuel": { "total_t": 150.0, "energy_gj": 6410 },
  "eu_ets": {
    "rated_co2e_t": 488.9,
    "ch4_n2o_included": true,
    "surrender_share": 1.0,
    "euas": 489,
    "cost_eur": 38142.00
  },
  "fueleu": {
    "attained_gco2e_mj": 87.02,
    "target_gco2e_mj": 89.34,
    "balance_gco2e": 14848000,
    "balance_t_vlsfoeq": 4.16,
    "penalty_eur": 0.00,
    "surplus_bankable": true,
    "surplus_value_eur": 1332.00
  },
  "cii": {
    "aer": 3.414, "required": 3.709,
    "ratio": 0.921, "rating": "B",
    "basis": "VOYAGE_ANNUALISED"
  },
  "constants_version": "2026.2"
}

Fleet balanceTypeScript

import { MeridianWake } from "@meridianwake/sdk";

const mw = new MeridianWake({
  token: process.env.MW_TOKEN,
  version: "2026-05-01",
  residency: "eu-central-1",
});

const balance = await mw.fleet.fuelEuBalance({ period: 2026 });

for (const v of balance.vessels.filter(v => v.deficit_t_vlsfoeq > 0)) {
  console.log(v.imo, v.deficit_t_vlsfoeq, v.penalty_eur);
}

// Pool the surplus against the deficit before 30 April.
await mw.fuelEu.pools.create({
  period: 2026,
  members: balance.vessels.map(v => v.imo),
  strategy: "MINIMISE_TOTAL_PENALTY",
});

Measured, not aspirational

42 msp50, /v1/voyages/estimate
118 msp95, same endpoint
240 msp99, same endpoint
6.4 sp95, 5,000 noon reports ingested and reconciled
99.97%Uptime, trailing 12 months, externally probed at 60 s
4 h / 15 minRecovery time and recovery point objectives

SOC 2 TYPE IIISO/IEC 27001:2022GDPR ART. 28

Your fleet data does not leave the region you choose.

Commercially sensitive voyage data is the most guarded asset an owner has. Residency is a contractual term, not a setting we can change without telling you.

Certifications

SOC 2 Type II, report period 1 Aug 2025 to 31 Jul 2026, independent CPA firm, available under NDA
ISO/IEC 27001:2022 certified, scope covers the platform, the data pipeline and corporate IT
ISO/IEC 27701:2019 for privacy information management
Annual penetration test by a CREST accredited firm, most recent March 2026, summary letter shared on request

Residency and encryption

Default residency eu-central-1, Frankfurt. Alternatives ap-southeast-1, Singapore and us-east-1, N. Virginia
Data at rest AES-256 with customer managed keys in AWS KMS, key rotation every 90 days
Data in transit TLS 1.3 only, HSTS preloaded, mTLS available for API clients
No cross-region replication of voyage data. Backups stay in the chosen region

Access and governance

SAML 2.0 single sign on and SCIM 2.0 provisioning on every tier
Role based access down to the vessel, with a separate read only role for verifiers
Immutable audit log, exportable via API, retained 7 years to match the MRV record keeping period
Sub-processor register published, 30 days notice before any addition

Data handling

GDPR Article 28 data processing agreement, standard contractual clauses Module 2 where relevant
Customer data is never used to train models, and never pooled into a benchmark without a signed opt in
Deletion on request inside 30 days, with a certificate of destruction
Personal data is limited to named user accounts and crew identifiers in noon reports, which can be pseudonymised on ingest

PRICINGEUR, EXCLUDING VATEFFECTIVE 2026-07-01

Priced per vessel, per month. The maths is on the page.

No implementation fee, no charge per API call, no charge for verifier seats. Annual term, 30 day exit if the first fleet reconciliation does not close.

Voyage

EUR 390per vessel, per month

1 to 24 vessels. Owners and operators running their first full compliance year.

ETS, FuelEU and CII engine
EU MRV and IMO DCS report generation
Full API and webhooks
Three data integrations
Verifier read only seats, unlimited

Fleet

EUR 310per vessel, per month

25 to 59 vessels. Falls to EUR 265 above 60. Commercial and technical teams working the same record.

Everything in Voyage
FuelEU pooling and banking optimiser
EUA position tracking against Union Registry holdings
Charterparty clause modelling, BIMCO ETS and CII clauses
Unlimited integrations, SSO and SCIM
Chosen data residency written into the contract

Verifier

EUR 18,000per year, plus EUR 95 per vessel-year audited

Accredited MRV and FuelEU verifiers and recognised organisations.

Cross-client read access with client consent
Sampling tools and exception queues
THETIS-MRV and FuelEU database export formats
Evidence bundle per vessel-year

A worked example, because per vessel pricing means nothing on its own

What the platform costs

34 Panamax bulkers on Fleet pricing34 × EUR 310 × 12
Annual platform costEUR 126,480

What it is pricing

Fleet CO₂, 15,500 t per vessel per year527,000 t
Average share inside EU MRV scope41%
2026 surrender obligation, 100%216,070 t
At EUR 78 per EUAEUR 16,853,460
Platform as a share of the carbon bill0.75%

A one percent error in the scope factor on that fleet is EUR 168,534. That is the entire platform cost, plus a third again, in a single misclassified voyage leg.

CHANGELOGPUBLICRSS AVAILABLE

Release history

Regulatory constants ship as minor versions and are always additive. Anything that changes a previously returned number ships behind a new date version.

3.14.09 Jul 2026

FuelEU pooling optimiser
Solve for the lowest total penalty across a pool of up to 400 vessels, including third party surplus offered on the marketplace. Returns the allocation, the settlement value per member and the borrowing position carried into the next period.
3.13.224 Jun 2026

Fix: gas carrier reference line boundary
Vessels between 64,000 and 66,000 dwt could be assigned the wrong CII reference line when the deadweight on the IOPP certificate differed from Q88. The engine now pins to the certificate value and records the source.
3.13.02 Jun 2026

Kpler bunker price feed
Delivered prices for 42 bunkering ports refresh every 15 minutes and now feed the voyage estimate directly, so the carbon and bunker legs of an estimate use the same timestamp.
3.12.014 May 2026

Indicative Z factors past 2026
Added 2027 to 2030 carbon intensity reduction factors as clearly labelled indicative values, so fleet planning does not stop at the end of the adopted schedule. Every response carries "z_basis": "INDICATIVE" where it applies.
3.11.08 Apr 2026

Q88 two way sync
Vessel particulars flow both ways. Changes to deadweight, main engine or fuel capability update the reference line and re-price the year to date automatically, with the previous value retained in the audit log.
3.10.026 Feb 2026

2025 true up and CH₄ accounting
Closed the 2025 compliance year at 70% surrender and opened 2026 at 100% with methane and nitrous oxide inside the scheme. LNG fuelled vessels on Otto cycle medium speed engines see rated CO₂e rise by up to 28%, because 3.1% slip counted at a methane GWP of 25 adds 0.775 t CO₂e for every tonne of gas burned. Two stroke diesel cycle installations are barely affected.

COMPANYOSLO AND SINGAPOREFOUNDED 2023

Built by the people who used to file these reports by hand.

Meridian Wake started in a fleet performance office in Bergen, in the first winter that EU ETS applied to shipping. The team spent that January rebuilding a spreadsheet every time a voyage crossed the scope boundary and it became obvious that the problem was not effort, it was that nobody had put the three regimes into the same model.

We are 34 people across Oslo and Singapore. Eleven have sailed or held a class or flag technical role. We are funded by a EUR 14M Series A led by a maritime specialist fund, closed in March 2026.

Sunniva LekvoldCo-founder and chief executive
Nine years running fleet performance for a Bergen owner with 61 vessels. Sat on the owner side of the first EU MRV verification cycle in 2018.
Arun PillaiCo-founder and chief technology officer
Built the emissions data pipeline at a classification society, ingesting noon reports from 4,000 vessels. Before that, distributed systems in payments.
Marta KowalHead of regulatory
Accredited EU MRV verifier for six years, then a flag state technical officer. Writes the constants review that goes out with every engine edition.
Tobias RaskHead of commercial
Chartering desk for a dry bulk operator, then carbon markets. Handles the charterparty clause work and the EUA side of the product.

QUESTIONSASKED IN EVERY FIRST CALL

The four questions that come up on every first call

Do you replace our verifier?

No. Verification is a statutory activity that only an accredited verifier can perform, and we are not one. What we do is get the evidence into a state where the verification is quick and boring. Customers report their verification cycle dropping from six weeks to nine days, mostly because the exception queue is empty by the time the verifier opens it.

Who is liable if the number is wrong?

The shipping company remains the responsible entity under Directive 2003/87/EC and under the FuelEU regulation. We carry professional indemnity cover of EUR 10M and we publish the constants, the source of every input and the calculation trace on every voyage, so a disputed number can be walked back to the bunker delivery note that produced it. In three years no customer has had a verified emissions report rejected on a figure the engine produced.

We already have a performance system. Why add this?

Performance systems answer how much fuel the ship burned. They rarely answer what that fuel costs you under three regimes with different scopes, different fuel treatments and different deadlines. We integrate with the performance system you have rather than replacing it, and most customers keep both.

How long does implementation take?

Median time from contract to first reconciled voyage is 11 working days for a fleet already on a supported noon report schema, and 26 days where the schema has to be mapped from scratch. Historical backfill of two years runs in the background and does not block go live.

Next step

Bring one real voyage. We will price it on the call.

Forty minutes. Send a noon report and a bunker delivery note beforehand and we will run your vessel, your lane and your fuel through the engine live, with the calculation trace on screen.

[email protected]

Oslo desk 07:00 to 17:00 CET · Singapore desk 08:00 to 18:00 SGT

One voyage.Three differentcarbon numbers.