The company expanded in the last 12 months through the acquisition of Dynamics Direct and Nvigorate.
Its UK revenues grew by 9% in the year to March 31 to reach £7.1m, and it won a number of contracts including those from a major building society, an insurance company, several retailers, an airline and a telecoms firm.
For the first time its US business accounted for approximately 50% of total revenues.
David Eldridge, chief executive of Alterian, said: "The company has achieved continued strong performance in the important North American market and the successful integration of our acquisitions."