Marital relations during ihram is the most severe violation of the ihram state. Scholars unanimously agree that if a pilgrim has sexual intercourse before the first tahalul (which occurs on the Day of Sacrifice after stoning Jamrat al-Aqabah, shaving/cutting hair, and either tawaf or sacrifice), the consequences are extremely serious. There are three mandatory consequences according to the consensus of the four schools:
First, the Hajj is invalidated (fasid). However, the pilgrim must complete all remaining rites of the Hajj as if it were valid — they cannot simply stop and go home. Second, the pilgrim must perform the Hajj again the following year to make up for the invalidated one, as the obligation of Hajj remains unfulfilled. Third, the pilgrim must pay a kaffarah, which according to the majority of scholars is sacrificing a camel. If unable to find or afford a camel, they sacrifice a cow. If unable, they sacrifice seven sheep.
Sheikh Ibn Baz explained that both spouses bear the sin if both were willing participants, and both must make up the Hajj. The kaffarah is shared between them according to one opinion, while another opinion requires a kaffarah from each. Sheikh Ibn Uthaymeen clarified that if the intercourse occurs after the first tahalul but before Tawaf al-Ifadah, the Hajj is not invalidated according to the majority, but the pilgrim enters a state of partial ihram, must exit the Haram to re-enter ihram from the nearest boundary, perform Tawaf al-Ifadah, and sacrifice a sheep. This is a lesser penalty than the pre-tahalul violation. Al-Fawzan noted that ignorance of the ruling does not excuse the violation in this case according to most scholars, given the severity of the prohibition.