What are the conditions for the validity of friday prayer?
1- To perform the Friday prayer in a residential area such as a village, town or city. The Friday prayer is not performed in places outside the residential area such as gardens, fields, etc. Those who live in plains far away from the village or the nomads cannot come together and perform the Friday prayer. If it is possible, they go to the nearest place where the Friday prayer is performed.
2- To perform the Friday prayer only in one mosque in one residential area. In residential areas in which the Friday prayer is performed in more than one mosque, believers should also perform the Noon prayer after the Friday prayer because one of the conditions for the validity of the Friday prayer will not be fulfilled.
3- To perform the Friday prayer by at least 40 sane, free, adult, and residing male Muslims. So much so that if there are not 40 qualified males living in a residential area, the Friday prayer does not become obligatory upon the residents of that area and the Friday prayer is not performed there. If hundreds of travelers come together in a mosque and if there are not 40 resident adult males among them, they cannot perform the Friday prayer in that mosque.
It is accepted as permissible to perform the Friday prayer if there are believers among the congregation, especially the imam, following another school of Islamic law, which does not require 40 people for the congregation for the validity of the Friday prayer. For the validity of the Friday prayer, the Maliki School requires at least twelve people, while the Hanafi School requires at least three male believers in addition to the imam. The latter is the view of Abu Hanifa and Imam Muhammad. According to Imam Abu Yusuf, two male believers in addition to the imam are enough to fulfill the requirement.
4- To perform the Friday prayer within the time of the Noon prayer.
5- To deliver a sermon before the obligatory cycles of Friday prayer. It is required that the imam should deliver a sermon and the congregation should listen to him.
6- One who is late for Friday prayer and catches the congregation while performing the second cycle is accepted to have attended the whole prayer. However, if he catches the prayer after the ruku’ in the second cycle, for example when the congregation is sitting for the testification of faith (tasahhud), it means he missed both cycles. Such a latecomer should stand up after the imam finishes the prayer by saying salams and perform the four-cycle Noon prayer.
Source: Fiqh1 (According To The Shafi’i School Of Islamic Law), Erkam Publications