Praise be to Allaah.
It is permissible to work
in booking hotels inside the Kingdom and abroad for those who want that,
unless it is known or thought most likely that they are travelling for
sinful purposes, or if the hotel is known for evil and corruption. In that
case, it is haraam to tell people about those hotels and it is also haraam
to help the one who wants to commit sin to do so, because Allaah says
(interpretation of the meaning):
“Help you one another in
Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one
another in sin and transgression. And fear Allaah. Verily, Allaah is Severe
in punishment”
[al-Maa’idah 5:2]
But in cases where you do
not know, or you do not think it most likely that a person is travelling for
sinful purposes, there is nothing wrong with you helping him to book a
hotel, and if his aim in doing so is for sinful purposes, then the sin will
be on him, not on you.
Please see also the answer
to question no. 117056 and
82402.
And Allaah knows best.