All the five legal schools agree that there are three kinds of Hajj: tamattu`, qiran, and ifrad. They also agree that by Hajj al-tamattu` is meant performance of the acts of the `Umrah during the months of the Hajj. The acts of the Hajj itself are performed after getting through the `Umrah. They also agree that by Hajj al‑'ifrad is meant performing the Hajj first and then, after getting through the acts of the Hajj, getting into the state of ihram for performing the `Umrah and its related acts. The four Sunni legal schools agree that the meaning of the Hajj al-qiran is to get into ihram for the Hajj and the `Umrah together. Then the talbiyyah uttered by the pilgrim is لبيك اللهم بحج وعمرة .
According to the Imamiyyah school, the Hajj al-qiran and Hajj al‑‘ifrad are one and the same. There is no difference between them except when the pilgrim performing the Hajj al-qiran brings the hady at the time of assuming the ihram. Then it is obligatory upon him to offer what he has brought. But one who performs the Hajj al‑‘ifrad has essentially no obligation to offer the hady.
In brief, the Imamiyyah do not consider it permissible to interchange two different ihram's,1 or to perform the Hajj and the `Umrah with a single niyyah (intention) under any condition; but the other legal schools permit it in Hajj al-qiran. They say that it has been named `al‑qiran' because it involves union between the Hajj and the `Umrah. But the Imamiyyah say that it is because of the additional feature of the hady accompanying the pilgrim at the time of ihram.2
According to the four Sunni legal schools, it is permissible for the pilgrim, Meccan or non‑Meccan, to choose from any of the three forms of the Hajj: al‑tamattu; al‑qiran, or al‑'ifrad, without involving any karahah (reprehensibility). Only Abu Hanifah considers Hajj al-tamattu` and Hajj al-qiran as makruh for the Meccan.
The four Sunni legal schools also differ as to which of the three kinds of Hajj is superior to the others. The best according to the Shafi`i school is al‑‘ifrad, and al‑tamattu` is superior to al‑qiran. According to the Hanafi school, al‑qiran has greater merit than the other two. The best according to the Maliki school is al‑‘ifrad, and according to the Hanbali and Imamiyyah schools is al‑tamattu`.
According to the Imamiyyah school, Hajj al-tamattu` is obligatory upon one living at a distance of over forty‑eight miles from Mecca, and he may not choose any other kind except in emergency. The Hajj al-qiran and Hajj al‑‘ifrad are performable by the people of Mecca and those living around it within a distance of forty‑eight miles, and it is not permissible for them to perform except one of these two kinds. The Imamiyyah base their argument on this verse of the Qur'an:
فَمَنْ تَمَتَّعَ بِالْعُمْرَةِ إِلَى الْحَجِّ فَمَا اسْتَيْسَرَ مِنَ الْهَدْيِ فَمَنْ لَمْ يَجِدْ فَصِيَامُ ثَلَاثَةِ أَيَّامٍ فِي الْحَجِّ وَسَبْعَةٍ إِذَا رَجَعْتُمْ تِلْكَ عَشَرَةٌ كَامِلَةٌ ذَٰلِكَ لِمَنْ لَمْ يَكُنْ أَهْلُهُ حَاضِرِي الْمَسْجِدِ الْحَرَامِ
…if any one wishes to continue the 'umra on to the hajj, He must make an offering, such as he can afford, but if he cannot afford it, He should fast three days during the hajj and seven days on his return, Making ten days in all. This is for those whose household is not in (the precincts of) the Sacred Mosque…..(2:196)
Moreover, according to the Imamiyyah school, it is not permissible for one obliged to perform the Hajj al-tamattu` to change over to something else, except for the problem of shortage of time available, or, in the case of women, due to impending menses. In those cases it is permissible to change either to al‑qiran or al‑‘ifrad on condition that the `Umrah is performed after the Hajj. The limit of the shortage of time is failure to be present at the wuquf in `Arafat until noon.
For one whose duty is al‑qiran or al‑‘ifrad, such as the natives of Mecca or those from its surrounding region, it is not permissible to change to al‑tamattu`, except in exigency (such as the fear of impending menses). After explaining this position of the Imamiyyah school, the author of al‑Jawahir says, "I have not come across any different opinion on this matter."
And all the five legal schools agree that the hady is not compulsory for one performing Hajj al‑'ifrad, though better if performed voluntarily.