We are going on Umrah and I want to know is it necessary to shave head hair fully or small cut is enough.
Men are allowed to shave as well as to trim the head hair, but shaving is desired, while the women will only trim (do qasr). In qasr, it is necessary to trim the hair equal to one third of a finger; otherwise the qasr will not be valid:
ثم یحلق أو یقصر والحلق أفضل ویکفی فیہ ربع الرأس والتقصیر أن یأخذ من رؤوس شعرہ مقدار الأنملۃ (مراقی الفلاح)
If the head hair of a man is so long which can cut equal to one third of finger, then he can get out of ihram by cutting, but if the hair are smaller, then it is invalid. (D)
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband