2023 U.S.-Booked Air Volume: $43 million
Consolidated U.S. TMC: Amex GBT

Financial services giant Citigroup in October 2023 selected American Express Global Business Travel as its new primary supplier of travel management services, switching from CWT.

Citi has worked to limit the environmental effect of its business travel by encouraging use of remote conferencing, while carbon dioxide equivalent emissions generated by the company's air and rail travel in 2022—the most recent available—increased by a nearly six times year over year to nearly 63,800 metric tons, a figure less than half of 2019 levels.

The company takes measures to raise awareness of emissions among travelers, including by offering emissions data at the point of booking and on travel invoices as well as communicating individual traveler footprints. Additionally, Citi also looks to raise awareness of the possibility of using electric cars for rentals while traveling.

Citi in 2023 agreed with American Airlines to transfer to Citi the emission reductions associated with Project Roadrunner, a sustainable aviation fuel production effort by manufacturer Infinium, backed by Citi and AA partner Breakthrough Energy Catalyst.

The company's 2023 revenue increased 4 percent to nearly $78.5 billion. Citi at the end of 2023 had about 239,000 full-time employees in 90 countries, compared with about 240,000 one year prior.