What is the consequence if a pilgrim has sexual intercourse after completing the Umrah but before the Hajj rituals are completed?
Chapter on Mentioning Hajj and Entering Makkah
Al-Mughni
Book of Hajj
Primary text
When sexual intercourse occurs after the pilgrim releases from Umrah (while intending to transition to Hajj), it is ruled that he has introduced Hajj upon Umrah, thereby invalidating the Umrah. All subsequent Hajj acts become void. The pilgrim is released from the invalid Umrah by performing the Tawaaf intended for Hajj. He must offer a penalty sacrifice for shaving/cutting hair due to the invalid Umrah, and a separate penalty sacrifice for the sexual intercourse committed during the invalidated Umrah. No valid Hajj or Umrah is achieved under this ruling.
Supporting text
If the act were ruled as occurring in the context of Hajj (assuming the Umrah Tawaaf was valid initially), then only the repetition of Tawaaf and Sa'i would be obligatory, and both Hajj and Umrah would remain valid.