Praise be to Allah.
There are various opinions on this matter.
Ibn al-Qayyim said:
The first view is that it is not permissible to give a fatwa based on taqleed [Translator’s note: Taqleed [lit. imitation] means repeating the views of scholars to others without knowing the details or basis of their fatwas] , because that is not knowledge, and giving a fatwa without knowledge is haraam. There is no dispute among people that taqleed is not the same as knowledge and that the muqallid (the one who imitates or repeats the views of others) cannot be given the name of ‘aalim (scholar). This is the view of most of our companions and the view of the majority of Shaafa’is.
The second view is that it is permissible with regard to himself; he may follow the view of one of the scholars if the fatwa is with regard to himself only. But it is not permissible for him to repeat the views of a scholar in giving a fatwa to someone else. This is the view of Ibn Battah and others among our companions. Al-Qaadi said: Ibn Battah mentioned in his letters to al-Barmaki: it is not permitted for a person to issue a fatwa based on what he had heard from a scholar who issued a fatwa. Rather it is permissible for him to follow that scholar’s view with regard to himself, but repeating his views and issuing a fatwa to someone else, this is not permitted.
The third view is that this is permitted when necessary and when there is no scholar who is qualified to make ijtihaad. This is the most correct view and this is our guideline. Al-Qaadi said: Abu Hafs said in his comments: I heard Abu ‘Ali al-Hasan ibn ‘Abd-Allaah al-Najjaad say: I heard Abu’l-Husayn ibn Bashraan say: what I may criticize a man for is learning five issues of fiqh from Ahmad then sitting by a pillar in the mosque [i.e., setting himself up as a scholar] and issuing fatwas based on that.