The new Carbon Savings Account Manager aims to help companies measure, track and reduce the carbon produced during their business travel, according to American Express.
The system, available to new and existing Amex commercial card holders, suggests alternative routes and modes of travel to reduce CO2 emissions.
It also reports back to stakeholders - such as travel and procurement managers, and finance officers - on the amount of carbon produced on trips.
It measures emissions based on the class of travel, route and length of the trip, and can report on any air travel completed within the year.
Karen Penney, Amex's VP business strategy and solutions, said: "Carbon SAM is a real step change for businesses looking to improving their sustainability."
Amex has spent 18 months developing the system, she said, "so that businesses can be confident the reporting on their business travel emissions is truly comprehensive."
www.americanexpress.com/corporate