Although more employers are refusing to pay for additional fees for employees on business trips, they're working with airlines on deals so workers don't have to foot the bill.

According to the 12th annual GetThere Corporate Travel Benchmark Survey, 78 percent are reimbursing for a first checked bag, compared to 95 percent in 2010. Reimbursement for on-board food and beverage dropped by 11 points to 42 percent, while Wi-Fi dropped by only one point to 50 percent.

"Companies told us they are reimbursing for fewer airline fees. However, employees are not necessarily being stuck with the bill," said Suzanne Neufang, general manager of GetThere. "Many corporations are likely negotiating away some of the ancillary fees charged by airlines and establishing firm travel policies around what they will and will not pay for."