The IMO Net-Zero Framework - FAQs

1. What is the IMO Net-Zero Framework?

The IMO Net-Zero Framework refers to a new set of international regulations aimed at reducing greenhouse gas (GHG) emissions from ships, in line with IMO's 2023 GHG Strategy. It has two main parts, which are linked:

1. A global fuel standard that requires ships to gradually reduce how polluting its ship fuel can be (i.e. how much greenhouse gas is emitted for each unit of energy used, across a fuel's life cycle); and

2. A pricing mechanism with set prices on the GHG ships emit, to encourage the industry to lower emissions to comply with the global fuel standard.
   

These regulations were approved as amendments to Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL), the IMO convention that sets rules for reducing air pollution from shipping and improving energy efficiency. These amendments were submitted with a view to adoption as legally binding measures in October 2025, during an extraordinary session of the Marine Environment Protection Committee. The MEPC met on 14-17 October and agreed to adjourn the meeting for one year until 2026.  

2. When does it take effect?

To become legally binding, amendments to the MARPOL Convention must go through several steps, usually through the "tacit acceptance procedure": 

submission → drafting → approval → circulation → adoption → deemed acceptance → entry into force → enforcement. (See more: Conventions)

The IMO Net-Zero Framework was approved by the Marine Environment Protection Committee (MEPC 83) in April 2025. The draft legal text was then shared with Member States for review, aiming for formal adoption at a special MEPC session in October 2025. Discussions have been adjourned until 2026.

Once adopted, under the tacit acceptance procedure, the regulations are expected to enter into force 16 months later at which point governments will be responsible for enforcing them.

3. What types of ships are covered?

The IMO Net-Zero Framework applies to all oceangoing ships over 5,000 gross tonnage (GT) - these ships are responsible for over 85% of global shipping emissions and are already covered by reporting requirements for fuel data collection. Ships under 5,000 GT are currently not covered, but discussions are underway to possibly include ships between 400 GT and 5,000 GT in the future.

4. How are ship emissions measured?

Ship emissions are measured using a metric called GHG Fuel Intensity (GFI). GFI calculates how much greenhouse gas is emitted for each unit of energy used, expressed in grams of CO₂ equivalent per megajoule (gCO₂eq/MJ). "CO₂ equivalent" means that not only carbon dioxide (CO2) emissions are covered, but also other greenhouse gases such as methane (CH4) or nitrous oxide (N2O). The framework covers emissions from the entire fuel lifecycle - from extraction and production to use on board the ship - known as the "well-to-wake" approach.

To make sure the data is accurate, traceable and credible, fuel emissions and sustainability must be independently verified through a Sustainable Fuel Certification Scheme recognized by the IMO's main environmental body, the Marine Environment Protection Committee (MEPC).

5. How exactly does the IMO Net-Zero Framework work?

The IMO Net Zero Framework sets up a global system where ships, regardless of their flag, must use cleaner fuels or technologies. If their GHG fuel intensity is too high, they will pay a price corresponding to the greenhouse gases they emit above  certain thresholds. Ships will get rewarded for using cleaner fuels. 

Ships must report their GHG Fuel Intensity (GFI) to the IMO each year. Each ship must keep its emissions below set GFI limits, which gets stricter every year.

If a ship exceeds set thresholds (there are two tiers of compliance), it must balance the excess "deficit" by using:

• Surplus units (transferred from other over-compliant ships or banked from previous years); or

• Remedial units (acquired by paying into the IMO Net-Zero Fund).

If a ship emits below a certain threshold, it can bank or trade its surplus units.

If a ship fully switches to zero or near-zero emission fuels, it qualifies for financial rewards.

6. What does a ship pay for emissions?

To allow ships to adapt successfully, there are two tiers of prices to be set for GHG emissions from ships, as outlined below. This would be applicable until a scheduled review. 

7. What is the IMO Net Zero Fund?

The IMO Net-Zero Fund will receive, manage and disburse collected revenue from GHG pricing contributions. These revenues will then be used to:  

• Reward low-emission ships;  

• Support innovation, research, infrastructure and just transition initiatives in developing countries;  

• Fund training, technology transfer and capacity building to support the IMO GHG Strategy; and  

• Mitigate negative impacts on vulnerable States, such as Small Island Developing States and Least Developed Countries.  

A governing board will be appointed to oversee the fund's daily operations. It will report back to IMO's Marine Environment Protection Committee on its activities.

8. What are ZNZ fuels?

ZNZs stand for "zero or near-zero" emission fuels, technologies or energy sources. Generally, ZNZs have a GHG Fuel Intensity (GFI) of no more than 19.0 gCO₂eq/MJ, which is 80% lower than the current average of 93.3 gCO₂eq/MJ. 

Ships that adopt ZNZs may be eligible for financial rewards from the IMO Net-Zero Fund.

9. Will the IMO Net-Zero Framework actually achieve the IMO's net-zero targets?

The IMO Net Zero Framework is intended to achieve the goals of the IMO's 2023 GHG Strategy, working alongside earlier GHG reduction measures (adopted in 2011 and 2021) which were focused on energy-efficient ship design, operational improvements and carbon intensity ratings. 

To ensure a successful transition, the framework takes a balanced approach that aims to:

• Send a clear demand signal to fuel producers;

• Reward first movers who adopt low- and zero-emission solutions early;

• Enable the existing fleet to adapt without undue penalties, considering global fuel availability;

• Support the most vulnerable States, including LDCs and SIDS, through the IMO Net-Zero Fund to advance shipping's energy transition.

As the GFI reduction requirements become increasingly stringent over time, this will encourage shipping firms to begin transitioning now, especially when planning new builds.

The IMO will review the IMO Net-Zero Framework every five years to assess its effectiveness and make any necessary adjustments. 

10. How will IMO keep track of progress?

A new digital IMO GFI Registry will be established to track each ship's compliance status, including:  

• Surplus units banked and remedial units acquired,  

• GFI calculations  

• Transfer and cancellation records.  
  

11. How will the regulations be enforced?  

Enforcement of all IMO regulations lies with the Member States, in their capacity as flag, port or coastal States. When a government accedes to an IMO Convention, it agrees to make it part of its own national law and to enforce it just like any other law.  

A Flag State must ensure that ships under its registry comply with IMO's international rules and standards, including safety, environmental protection and labour conditions.

A Port State has the right to inspect foreign ships in national ports to verify that compliance with IMO rules.

All Member States are audited approximately every seven years to ensure they are complying with IMO obligations. 

Furthermore, Member States, in coordination with the IMO and other global bodies, will be encouraged to provide technical assistance, technology transfer and capacity building, particularly to developing States seeking support for implementation. 

12. How does voting work at IMO?

At IMO, decisions are usually taken by consensus, meaning there is general agreement among Member States without formal objection and votes. If consensus cannot be reached, any Member State may request that the matter be put to a vote.

Within IMO Committees, such as the Marine Environment Protection Committee (MEPC), decisions are taken by a simple majority of Member States that are present and voting. However, when the decision concerns the adoption of an amendment to a treaty, the voting rules are determined by the treaty itself.

In the case of the MARPOL Convention, an amendment must be adopted by a two-thirds majority of the Parties to the Convention that are present and voting. For issues relating to the IMO Net Zero Framework, this means only Parties to MARPOL Annex VI (the 1997 Protocol) may vote. There are currently 108 such Parties, representing over 97% of the world’s merchant shipping fleet by tonnage.

When voting, only “yes” and “no” votes are counted. Abstentions may be recorded in the meeting report, but they do not count towards the two-thirds majority.

Under the tacit accceptance procedure, once an amendment has been adopted, it is deemed accepted at the end of a minimum period of ten months, unless within that period objections are made by no less than one third of the Parties OR by Parties with a combined merchant fleet tonnage of not less than 50% of world tonnage. If neither condition is triggered, the amendment is considered accepted.

Following acceptance, the amendment enters into force six months later. At that point, it becomes binding on all Parties except those that formally objected, and responsibility for enforcement rests with national Governments.

Access documents

To access the IMO Net-Zero Framework approved draft regulations and all documents for MEPC Extraordinary Session 2, please visit IMODOCS and create your free account.