Freight buyers should prepare for the outcome of the International Maritime Organization’s forthcoming Net-Zero Framework vote because the resulting carbon costs will ultimately reach those paying shipping bills, according to Tom Isler, ESG and innovation director at Baxter Freight.

Isler argues that the vote is likely to be presented primarily as an issue for shipowners, focusing on fuel standards, carbon levies and flag-state positions. However, he says shippers will bear costs under either outcome and that a failure to establish global rules could prove more expensive and administratively difficult.

The proposed framework would introduce a common approach to greenhouse gas intensity and carbon pricing for ships representing almost all global tonnage. It was approved in principle in April 2025 and had been scheduled for adoption the following October. That session was instead adjourned by 57 votes to 49 amid political pressure.

Technical work on supporting guidelines has since reduced some of the outstanding differences, although the political issues remain unresolved. If the framework is adopted, its requirements would take effect no earlier than 2028.

According to Isler, a single global standard would allow freight buyers to assess carbon costs using a consistent methodology across carriers and trade lanes. This could make quotations easier to compare, help buyers determine whether variations reflect operational efficiency or different accounting methods, and support more defensible budgeting for 2028.

He notes that a global framework would not remove the cost of shipping decarbonisation. Those expenses would still be reflected in freight rates. The advantage for cargo interests, he argues, would be improved visibility, forecasting and the ability to challenge charges rather than receiving poorly explained surcharges.

Failure to adopt the framework would also not eliminate carbon pricing from shipping. The EU Emissions Trading System’s maritime coverage and FuelEU Maritime are already in force and appearing on invoices. Without an international regime, Isler expects other jurisdictions to be more likely to develop separate measures.

Such a patchwork could expose individual shipments to several surcharges calculated under different systems and applied inconsistently by carriers. Carbon costs could also vary according to routing and port calls. Shippers and freight forwarders could consequently face additional administrative work, while emissions figures generated under separate schemes may not align.

This could create particular difficulties for companies seeking to support Corporate Sustainability Reporting Directive obligations or document Scope 3 emissions targets. Greater complexity may also make carrier charges harder to scrutinise.

Ahead of the October vote, Isler recommends that freight buyers identify the carbon schemes affecting their lanes, require tenders to itemise carbon costs and explain the methodology used, and improve emissions-data collection. He also advises businesses to model both possible outcomes in their 2027 and 2028 budgets rather than waiting for the final decision.

His central warning is that the absence of an IMO agreement would not mean the absence of carbon costs. Instead, freight buyers could face a less transparent and more fragmented system for calculating and passing those costs through the supply chain.