Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. – Volume 13, Page 67, Question No.3 of Fatwa No.7359
Question: What is the ruling regarding trading in women’s beauty items [inclusive of clothing], and selling them to women whom the sales assistant knows will wear them to beautify themselves in front of non-mahram men in the streets, as he sees her state in front of him, and as is unfortunately widespread in some cities (places).
Response: It is not permissible to sell them if the sales assistant knows the person who buys them is going to use them for things that Allaah has forbidden, because this means that he is co-operating in sin and transgression. But if he knows that the buyer is only going to wear them for her husband or he does not know anything, then it is permissible for him to sell them.
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet (sal-Allaahu ‘alayhi wa sallam) and his family and his companions.