It is clear from the Holy Qur'an and the traditions that performance of Hajj (Pilgrimage) is obligatory on every person who has attained puberty and has the means mentioned below.
Hajj is one of the basic principles of Islam; its performance is one of its essentials, and its non-performance is a grave sin. Denial of the obligatory nature of Hajj is blasphemy (kufr). Allah states in the Holy Qur'an,
“.. and pilgrimage to the House is incumbent upon men for the sake of Allah, (upon) every one who is able to undertake the journey to it; and whoever disbelieves, surely Allah is Self-sufficient, above any need of the worlds”. (3/97).
Sheikh Kulayni has reported that Imam as-Sadiq (a.s.) has said, “Whoever dies without having performed obligatory pilgrimage when he was not prevented by lack of means, illness, or force, dies a Jew or a Christian”. Indeed, there are many hadiths (traditions) on pilgrimage being obligatory and on its importance, but the brevity of this work does not permit setting them all out.
In religion the performance of pilgrimage is obligatory on a person once only; it is known as ‘Hajjatul Islam’.
Rule 1: Performance of pilgrimage becomes obligatory immediately in the year in when its conditions are realised. If one fails to perform it, deliberately or for an excuse, it must be fulfilled in the ensuing year, and so on. Postponing it without valid reason is a grave sin.
Rule 2: When performing pilgrimage becomes obligatory, one must make all the arrangements for the journey to ensure the performance of the ceremonies in time. If there are several groups one could join, by any means of travel, so much so that one is confident to reach in time, it is permissible to join any one of them or take any route; yet it is preferable to choose the one that would definitely get you there in time.
Rule 3: If it was possible for a person to make the journey in the same year, pilgrimage becomes obligatory, even if leaving it to the last minute, in the hope that they would reach in time. However, if the person was not able to get there in time for pilgrimage, the obligation to perform it, most evidently, does not become obligatory on them, even though their delay was excusable.