Hey,

am I allowed to sell textures I made for requests, which are unwanted?

EinVasalle

If you paid for them and still have possession of them, yes. They are yours and you are free to do what you want with them.

If you fairly bought these texture by request or however, you can sell them cos now you have a right of ownership on them. But don't forget to put the name of the artist when sellling ;)