This includes Belfast International Airport, Wrightbus and Lisburn & Castlereagh City Council in Northern Ireland; and the National Aquatic Centre, and Department of Transport, Tourism & Sport in the Republic of Ireland.
As well as helping to increase the company’s turnover by 20% for the financial year 2017/18 (to £40m), it also marks over 10 years of growth.
Chairman and founder Trevor Annon said: "Over the past 12 months, Mount Charles has secured a substantial number of new contracts.
“Our growth in turnover in a competitive marketplace is a hugely encouraging indicator that we are on course to achieve our target of £100m in revenue by 2025.
“There is certainly still room for growth in Northern Ireland, but growing our market share in the Republic will be a major driver for overall company expansion over the next five years.
“We are delighted with the progress that we’ve made in the last year and, thanks to increased infrastructure and a focus on strategic talent acquisition in Dublin, we believe that we’re in a strong position to push forward in Ireland in the year ahead.”