It is permissible to have a down payment

Q 2: I work in the postal service and I sell stamps. What is the ruling on selling stamps for more than their actual price?

It is not permissible for a person who is working in the post office to sell stamps with a price that is more than their actual price. He has to sell them according to the price written on the stamps without any increase or decrease. He is considered to be a trustee for doing that. Selling them for a price more than the price written on them is a betrayal of the trust he was given. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.