Business Travel Emissions Regulations: How New U.S. and EU Rules Will Change Corporate Reporting

Business travel falls under Scope 3 emissions. U.S. federal climate disclosure requirements have stalled under the Trump administration, but California state laws and EU regulations are moving forward. The Corporate Sustainability Reporting Directive (CSRD) brings mandatory disclosures based on ESRS standards and double materiality, including Scope 3 business travel. 

Here's what to expect in 2025, how EU rules reach U.S. companies, and how to build reporting systems that work across jurisdictions.

What is the current status of U.S. climate disclosure rules?

The SEC adopted climate disclosure rules in March 2024, but they have never taken effect. The SEC voluntarily stayed the rule after legal challenges, and on March 27, 2025, voted to end its defense of the rules under the Trump administration. On July 23, 2025, the SEC told the Eighth Circuit it "does not intend to review or reconsider the Rules at this time" and stated that a majority of Commissioners believe the rule "lacks statutory authority". The rule remains in legal limbo, not formally rescinded but effectively abandoned.

The original SEC rule would have required large filers to disclose material Scope 1 and Scope 2 emissions, governance structures, and climate risks. Mandatory Scope 3 reporting was removed from the final rule. Companies won't report under the SEC rule unless courts unexpectedly uphold it and a future administration enforces it.

California has separate, more comprehensive requirements. SB 253 (Climate Corporate Data Accountability Act) requires companies with over $1 billion in revenue doing business in California to disclose Scope 1, 2, and 3 emissions starting in 2026. SB 261 (Climate-Related Financial Risk Act) requires biennial climate risk reporting for companies over $500 million, with first reports due January 1, 2026. On August 13, 2025, a federal court declined to block enforcement of these laws, so they proceeded on schedule. Over 3,100 companies appear on CARB's preliminary covered entity list.

How the EU CSRD affects U.S. companies

CSRD applies through European Sustainability Reporting Standards (ESRS). Large EU entities began reporting on FY2024 data in 2025. Non-EU companies with significant EU revenue (over €150 million) and at least one EU subsidiary or branch report at the consolidated level starting with financial years beginning in 2028, with reports due in 2029.

CSRD uses double materiality, financial and impact materiality. This often makes Scope 3 Category 6 (business travel) material for service companies. ESRS E1 requires Scope 1, Scope 2 (market-based and location-based), and material Scope 3 categories. Companies must disclose methodologies, data sources, and key assumptions. These disclosures require independent assurance.

U.S. companies in scope should map GHG inventories to ESRS data points. Document estimation techniques for travel when primary data are incomplete.

Will travel emissions thresholds become stricter?

Neither the abandoned SEC rule nor CSRD sets fixed thresholds for business travel reporting. Materiality determines reporting requirements and granularity. ESRS requires disclosure of material Scope 3 categories with clear methodology, creating expectations for mode-level detail (air, rail, road), class-of-service in aviation, and treatment of well-to-tank and radiative forcing effects.

The Science Based Targets initiative (SBTi) indirectly tightens requirements. If Scope 3 represents 40% or more of total emissions, companies must set Scope 3 targets. Business travel routinely falls in scope for service companies.

ISO 14083:2023 standardized transport emissions accounting. Recognized tools now provide activity-based aviation factors. Companies are moving from spend-only calculations to distance- and equipment-specific models.

How to make reporting across regions consistent. 

Build one inventory that meets all requirements. Start with the GHG Protocol Corporate Standard and Scope 3 Standard. Document boundaries, base year, consolidation approach, and estimation hierarchies for travel. Maintain both market-based and location-based Scope 2 results.

For business travel, prioritize activity data from travel management companies, airline and rail APIs, and car rental partners. Use distance- or spend-based factors only when primary data aren't available.

Map a single dataset to multiple outputs: ESRS E1 for CSRD, California SB 253 and SB 261 requirements, and voluntary IFRS S2 reports for investors. Keep narrative and metrics synchronized. If you use Sustainable Aviation Fuel (SAF) book-and-claim certificates, disclose them separately from gross emissions and explain safeguards against double counting.

Compliance risks with delaying methodology updates

Delays create four problems: material misstatements as Scope 3 travel grows, audit failures due to weak data lineage, jurisdictional non-compliance where Scope 3 is mandatory, and reputational risk from perceived greenwashing.

Under CSRD, assurance providers will challenge inconsistent boundaries, outdated emission factors, and unclear estimation choices. Even without SEC requirements, companies making voluntary climate statements face anti-fraud scrutiny under U.S. securities law. California's laws impose mandatory reporting with potential penalties for non-compliance.

Procurement and finance teams may struggle to answer investor or customer questionnaires without structured, mode-level data. This delays deals and increases cost of capital.

Playbook for business travel related emissions

Collect detailed travel activity data for every employee trip: total distance traveled by mode (air, rail, car), class of service (economy, business, first), aircraft or vehicle type, and passenger load. Pull this information from travel management system records or directly from airlines, rail operators, and rental partners. Detailed activity data enables accurate, mode-specific calculations.

Apply mode-specific emission factors to each trip. For flights, use aircraft-, route-, and cabin-specific factors where available. For rail and road, incorporate region-specific factors and well-to-tank emissions. Choose whether to include radiative forcing for aviation and document that choice.

When activity data are missing, use spend-based emission factors as a fallback, applying Environmentally Extended Input-Output factors to total travel costs. Always disclose when and where spend-based methods were used instead of activity-based calculations.

Engage suppliers early to improve primary data. Place contract clauses requiring emissions-ready reporting. Pilot SAF certificates through credible book-and-claim channels while keeping them separate from gross inventory totals.

Set trip approval thresholds, designate rail-first corridors for short distances, and define when virtual meetings should replace travel. Disclose these policies so investors and customers can see how travel decisions connect to emissions outcomes. See how to build a sustainable business travel strategy for practical frameworks and ways to reduce business travel emissions for high-impact measures.

For EU reporting timelines, Dyme's CSRD timeline for U.S. companies covers scoping, first-year reporting, and assurance phasing. Companies that document assumptions, standardize on GHG Protocol methods, and test data systems for audit readiness will spend less time revising past reports and more time reducing actual travel miles.