The school was recognized by the State of Haryana in the year 1999. It was later affiliated to the Central Board of secondary Education in 2001. The first batch of X passed out in the year 2003. Each year brings more successful results and St. Thomas has even gone on to achieve both 3rd and 6th rank in the All India Secondary School Examination in the same year. Since 2007 based on the demand of parents and students of Bahadurgarh, St. Thomas school started batches for XII graders who found it