1) The Madrasha lead by Ulama-e-su (hypocrite Maolana) and are related to terrorism, fundamentalism and other Kufrism. Giving Zakat will not be valid and considered if it is given to those Madrasah.
2) Zakat may not be given to a man who is owner of Nisab (fixed limited) wealth or a rich man.
3) According to the the Imam and Mujtahid of Muta'akaddimin It is not allowed to take Zakat for the descendents of Hazrat Abbas, Jafor and Aqil Radiallahu Ta'ala Anhum of Banu Hashim of Quraish. But according to The Imaam and Mujtahid of Ahle Sunnat Wal Jamaat it is allowed (Halal).
4) Zakat can not be given to non Muslims.
5) The Zakat may be given to those Madrasa where there are Lillah boarding and orphanage. But where there is no Lillah boarding and orphanage Zakat can not be given to those Madrasa.
6) Zakat can not be given to poor parents, on behalf of children, husband and wife.
7) If the Zakat collector is appointed by the institution, for Lillah boarding or orphanage then the Zakat can not be given to that Zakat collector.
8) If an earning person is devoted to perform Nafl Salat, Saom (fasting) and other nafal prayers not earning himself then Zakat can not be given to him. But if he is suitable to take Zakat for having no income source then Zakat can be given to him.
9) Zakat can not be given to servants as their salary