Scope 3 category 6: business travel emissions and radiative forcing

Business travel is often the first Scope 3 category a company calculates, because travel bookings already record where people went and how. It is part of the value chain covered in the 15 Scope 3 categories.

What is in category 6

The GHG Protocol's guidance describes category 6 as emissions "from the transportation of employees for business-related activities" in vehicles "owned or operated by third parties": flights, trains, taxis, buses, ferries, hire cars and employees' own cars used for work.

Two boundaries matter:

• Company vehicles are not category 6. Travel in vehicles the company owns or controls is "accounted for in either scope 1 (for fuel use), or in the case of electric vehicles, scope 2 (for electricity use)". See Scope 1 emissions.
• Hotels are optional. "Companies may optionally include emissions from business travelers staying in hotels." If you include them, say so.

Three methods

The guidance lists three ways to calculate category 6:

The distance-based formula is the sum over each mode of distance travelled (passenger-km or vehicle-km) × the emission factor for that mode, plus, optionally, hotel nights × a hotel factor.

Flights and radiative forcing

Flying also affects the climate through non-CO2 effects at altitude, usually summarised as radiative forcing. The guidance says "multipliers or other corrections to account for radiative forcing may be applied" and, "If applied, companies should disclose the specific factor used."

DESNZ publishes flight factors both with and without radiative forcing (RF). For an economy short-haul flight to or from the UK, the 2026 factors are 0.12576 kg CO2e per passenger-km with RF and 0.07435 without: including RF raises the result by about 69%. Pick one, state it in your report, and keep it the same each year.

DESNZ also publishes factors by cabin class. Long-haul economy is 0.11704 kg CO2e per passenger-km with RF, while the long-haul "average passenger" factor across all classes is 0.15282.

Worked example

Two employees each make two return trips of 1,000 km each way by air, stay six nights in Italy in total, and take 800 km of UK train journeys. DESNZ 2026 factors:

Without radiative forcing, the flights would be 595 kg and the total 706 kg. The trains for 800 km emit about as much as 200 km of flying.

Data to collect

• Flights: origin, destination, cabin class. Your travel agent can usually export distances; otherwise calculate great-circle distances between airports.
• Rail, bus, coach: distance, or origin and destination.
• Cars: distance from mileage claims, fuel type and car size if known. An employee's battery electric car has a DESNZ business-travel factor of 0.02951 kg CO2e/km, not zero, because the charging electricity is not in your Scope 2.
• Hotels: room-nights by country.

Also report the upstream part

Distance factors cover the vehicle's direct emissions. In LCALens, saving a business travel calculation lets you also save the matching well-to-tank factor (fuel production) as a linked calculation in the same category, so the full well-to-wheel figure is available without mixing the two.