All Sunni and Shia 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.
According to the Imami 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 Imami 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.
According to the Imami 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.