The company – part of Capita Group – has recorded profits of £2,032,893 to the end of December 2010, with turnover at £11,658,729.
The previous year, profits were £1,439,626 and turnover was £10,636,813.
Capita Group acquired BSI for £42.5m in December 2010 and Trevor Elswood is now managing director of both businesses.
James Parkhouse remains as director for travel and conferences within Capita and he and Elswood are now working closely to develop the business.
Parkhouse told C&IT the figures had been helped by "increasing business confidence" in the industry.
"The [improvement] is down to a combination of new account wins and increased customer activity," he said.
Capita Business Travel won the Eon account in autumn 2010, while Royal Mail has been a client since 2002.
The latest figures return Capita Business Travel to 2008 levels, when turnover was £11,630,377 and profits stood at £1,732,744.