All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
There are three important rulings concerning the folks of the Prophet(Peace be upon him):
1. Sending prayers upon them along with the Prophet(Peace be upon him) while performing prayer.
2. They aren't among the eligible recipients of Zakah (Alms).
3. They should give one-fifth of the fifth.
As for sending prayers upon them along with the Prophet(Peace be upon him) while performing prayer, jurists agreed on its permissibility since Ka'ab Ibn Ojra'(May Allah be pleased with him) said:" "We asked Allah's Messenger (Peace be upon him) saying, 'O Allah's Messenger (Peace be upon him)! How should one (ask Allah to) send blessings on you, the members of the family, for Allah has taught us how to salute you (in the prayer)?' He said, 'Say: O Allah! Send Your Mercy on Muhammad and on the family of Muhammad, as You sent Your Mercy on Abraham and on the family of Abraham, for You are the Most Praise-worthy, the Most Glorious. O Allah! Send Your Blessings on Muhammad and the family of Muhammad, as You sent your Blessings on Abraham and on the family of Abraham, for You are the Most Praise-worthy, the Most Glorious.' " [Agreed upon].
As regards scholars' consensus concerning the permissibility of the aforementioned prayer, some of them considered it a pillar of prayer while others considered it an act of prayer`s Sunnah.
Furthermore, the old Shafie' school is of the view that sending the aforementioned prayer is similar to sending prayers upon the Prophet (Peace be upon him) which is an act of Sunnah in the first Tashahhud, but obligatory in the second.
As for the modern Shafie' school, its scholars considered sending those prayers on the Prophet's folks an act of Sunnah while performing prayer and not sending them won't render that prayer invalid. In addition, this opinion is adopted by the majority of Muslim jurists. Kindly refer to [Mughni Al-Muhtaj 1/380].
Moreover, giving one-fifth of the fifth by the Prophet's folks is adopted by the majority of the righteous companions( May Allah be pleased with them). Please refer to [Hashyat Al-Bajermi A'laa' Al-Iqnaa']. And Allah knows best.