What do the respected scholars and esteemed muftis say regarding the following issue that, Respected Sir, I am a teacher at a school. For the past two to three years, we have been receiving funds for the school, and it is clearly mentioned that up to ten percent of the amount may be taken by the teacher as traveling allowance. However, the actual yearly expenses incurred by the teacher while working for the school are at most around 3,000 rupees. But if the teacher receives a fund of 100,000 rupees, he takes 10,000 rupees, based on the claim that 10% is allowed for the teacher. In this case, is it permissible (halal) for the teacher to take the full 10,000 rupees?
It is necessary for the questioner and his colleagues to act according to the agreement made with the school administration. However, if the administration has fixed the traveling allowance at ten percent in all cases regardless of whether the actual expense is less or more then in such a case, taking the full ten percent as traveling allowance will also be permissible
کمافی المعجم الکبیر: عن عبداللہ بن عوف المزنی،عن ابیہ، عن جدہ عن رسول اللہ ﷺ قال:المسلمون علیٰ شروطھم الا شرطاً حرم حلالاً واحل حراماً والصلح جائز بین الناس،الا صلحاً احل حراماً او حرم حلالاً اھ(ج14/ص22)۔