1-Islam: Prayer is not valid if performed by an unbeliever.
2-Sanity: Prayer is not valid if performed by an insane person.
3-Puberty: It is not required of a child until he or she attains puberty.
4-Purification: From any discharge that invalidates ablution.
5-Appropriate time: Each prayer has its appointed time range and for a prayer to be valid.
6-Covering the awrah, which is the private parts and the area around them.
7-Avoiding all impurity on one’s body, clothes and the place where one is praying.
8-Facing the qiblah (i.e. the direction towards the Ka bah) when one is able to do so.
9-Intention: The intention is a mental process and need not be vocalized.