US businesses pay around £350 in mobile roaming charges for each employee that travels on a single business trip to Europe or Asia.
The figure may indicate how UK companies are paying through the nose for their staff's long-haul international travel too.
An independent study commissioned by global mobile comms provider Brightroam, says the cost of a single trip outside the US is the equivalent of 12 times the amount of a month's average wireless bill in the US, for each employee.
Surprisingly though, says the research, few US businesses report plans to look for more affordable options.
Jeff Wilson, general manager at Brightroam, said, "The study shows that 15% of employees make at least one international trip per year, which translates into costs of more than £475,000 annually per 10,000 employees.
"If you consider that many large businesses in the US employ more than 30,000 employees, it is easy to see how roaming costs can take a big bite out of operating costs."