There is nothing wrong with opening barbershops for men or engaging in this profession, so long as one avoids haraam things such as shaving beards, removing any part of the eyebrows or cutting the hair in styles that resemble kaafirs. See question no. 34722 and 1189.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked: Someone is saying that he has a relative who owns a hair salon that is rented out to an agent and he advised him that this work is haraam, and that the money earned is haraam, and that it is not permissible to shave Muslims’ beards. He said: I do not take anything from the agent except the rent for the store, one hundred and fifty riyals, and the people are free to shave their beards, and I do not force them to have them shaved by him.
If he writes and posts a notice in this salon saying that it is not allowed to shave beards, and if anyone who asks to have his beard shaved, he refuses to do that, then there is nothing wrong with seeking provision from Allaah. But if he will shave the heads and beards of anyone who asks, then it is not permissible, and he should change this salon into something better. The one who gives up something for the sake of Allaah, Allaah will compensate him with something better than it. To sum up:
Opening salons and barbershops is subject to further discussion. If the person will refuse to shave that which it is haraam to shave, there is nothing wrong with it, as it is a means of earning a living. But if he will shave whatever the customer asks him to shave, even if it is haraam, then it is not permissible. End quote from Liqa’ al-Baab il-Maftooh (79/13).
He (may Allaah have mercy on him) was also asked: I have some stores and I want to rent them out to some salons and barbershops. Is there anything wrong with that?
He replied: There is something wrong with that if you rent the stores to barbers as it is well known that barbers usually shave everything; they shave heads and beards and they may shave beards more than heads as this is the norm. Based on this, it is not permissible to rent out stores to barbers unless you stipulate that they should not shave beards; in that case there is nothing wrong with it. If it is proven that he shaved beards in this store then the landlord of the store will have the right to cancel the contract, because the renter agreed to a valid condition but did not fulfil it. This is the answer to renting out stores to barbers, i.e., it is not permissible to rent them to them unless it is stipulated that they should not do anything haraam in them such as shaving beards, because renting to them is helping them in doing this haraam action, and Allaah says (interpretation of the meaning): “do not help one another in sin and transgression” [al-Maa’idah 5:2]. The fact that it is haraam to rent to them is also indicated by the fact that the Prophet (peace and blessings of Allaah be upon him) said: “When Allaah forbids a thing, He also forbids its price” and the rent is the price that the renter gets for use of it.
End quote from Fataawa Noor ‘ala al-Darb.
And Allaah knows best.