What is the ruling, according to the Hanafī school, on someone, male or female, who forgot to shorten their hair (taqṣīr) after assuming the state of iḥrām, then remained in Mecca or went outside of it?

The meaning of "forgot to shorten the hair after ihram" is unclear, as shortening the hair or shaving is done after the circumambulation (tawaf) and the ritual walking (sa'i) in Umrah, and on the Day of Sacrifice (Yawm al-Nahr) in Hajj, not immediately after ihram. Taking hair after ihram is prohibited.

If what is meant is forgetting to shave or shorten the hair after Umrah or during Hajj, then according to the Hanafis, shaving or shortening the hair is obligatory for exiting the state of ihram, and whoever does not shave or shorten their hair remains in their state of ihram.

If the pilgrim wears his clothes before shaving, it is a transgression. If he continues wearing them for a full day, he must offer a sacrifice (dam). If it is less than a day, then a charity (sadaqah) is due. There is no difference in the obligation of the transgression between intentionality, forgetfulness, or ignorance.

In Hajj, shaving is time-bound (the days of sacrifice) and place-bound (the Haram). Whoever performs shaving outside its designated time or place must offer a sacrifice. As for Umrah, shaving is not time-bound, but place-bound. So, if one shaves outside the Haram, he must offer a sacrifice.