No, both are, in terms of prestige, equal. The only main difference between them is that ACCA is more flexible in that you do not need to obtain a training contract in order to sit the exams; whereas with ICAS you do. Both are chartered, both have similar syllabus, and both require 3 years practical experience. Some people say that ACCA is easier because the pass rate is 50% instead of ICAS' 55%. If you ask markers, though, most will agree that ACCA exams are slightly more difficult. P2 corporate reporting is an exceptionally difficult paper. In reality, companies will not differentiate between the two.