Answered by Shaykh Yūsuf Badat
I have a personal dilemma and hope you can guide me in the right direction. I am a Ḥāfiz, alḥamdulillāh, so need to, and hope to lead tarāwīḥ.
The question is about my haircut. For personal reasons, I have my haircut short back and sides, longer on top. The hair on the side and back, when I have my topī on, looks level, such that my scalp cannot be seen.
The hair on top is kept long enough to comb and be presentable. The difference in length between the back and side hair and the hair on top of my head is approximately 2 cm.
The question is, am I allowed to lead tarāwīḥ in this way? I do want lead tarāwīḥ but I also feel very uncomfortable in keeping my hair short all around.
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allāh, Most Gracious, Most Merciful.
Jazāk Allāh Khayr/ Thank you for contacting Mathabah.
It is permissible for you to lead tarāwīḥ despite having an uneven haircut. This does not fall under the “qazʿaʾ” haircut which the Prophet Muḥammad (peace and blessings be upon him) prohibited.
The “qazʿaʾ” haircut refers to shaving parts of the hair on the head while leaving other parts unshaven. This is prohibitively disliked (makrūh tanzīhī). – (See: Rad Al-Muḥtār, Vol 6, Page 407, Dār Al-Fikr) 
It should be borne in mind that when you are adopting a lofty position of leading prayers, you should try your best to adhere to sunnah practices of the Prophet Muḥammad (peace and blessings be upon him).
“The Messenger of Allāh (peace and blessings be upon him) said, “Let the one who has most knowledge [and practice] of the Book of Allāh lead the people in prayer. If they are equal in terms of knowledge of the Qur’ān, let the one who emigrated first [lead them]. If they are equal in terms of emigration, let the one who has more knowledge [and practice] of the sunnah [lead them]. – (Nasa’ī 780)
“The Prophet (peace and blessings upon him) forbade qazʿaʾ (to shave part of the head and leave other parts).” – (Nasaī 5228)
Ibn ʿOmar reported that Allāh’s Messenger (peace and blessings upon him) forbade qazʿaʾ. Nafiʾ(Ibn ʿOmar’s student) explained, “This means having a part of a boy’s head shaved and leaving a part unshaven.” – (Ṣaḥīḥ Muslim 2120)
Only Allāh knows best.
 وَيُكْرَهُ الْقَزَعُ وَهُوَ أَنْ يَحْلِقَ الْبَعْضَ وَيَتْرُكَ الْبَعْضَ قَطْعًا مِقْدَارَ ثَلَاثَةِ أَصَابِعَ كَذَا فِي الْغَرَائِبِ – كتاب الدر المختار وحاشية ابن عابدين ج٦/ ص٤٠٧ دار الفكر
يَؤُمُّ الْقَوْمَ أَقْرَؤُهُمْ لِكِتَابِ اللَّهِ فَإِنْ كَانُوا فِي الْقِرَاءَةِ سَوَاءً فَأَقْدَمُهُمْ فِي الْهِجْرَةِ فَإِنْ كَانُوا فِي الْهِجْرَةِ سَوَاءً فَأَعْلَمُهُمْ بِالسُّنَّةِ – النسائي ٧٨٠
 عَنِ ابْنِ عُمَرَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم نَهَى عَنِ الْقَزَعِ – النسايي ٥٢٢٨
 عَنْ عُبَيْدِ اللَّهِ أَخْبَرَنِي عُمَرُ بْنُ نَافِعٍ عَنْ أَبِيهِ عَنِ ابْنِ عُمَرَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنِ الْقَزَعِ قَالَ قُلْتُ لِنَافِعٍ وَمَا الْقَزَعُ قَالَ يُحْلَقُ بَعْضُ رَأْسِ الصَّبِيِّ وَيُتْرَكُ بَعْضٌ – مسلم ٢١٢٠