Whoever takes unlawful money and then repents to Allah, should return the money to its owner if possible. Otherwise, he should give it in charity intending its reward to go to the owner of the money, with a deep feeling of remorse, seeking Allah's Forgiveness and determine never to repeat this because Allah (Exalted be He) states:
And eat up not one another’s property unjustly (in any illegal way e.g. stealing, robbing, deceiving, etc.)
An employee (Part No. 23; Page No. 588) who takes money from clients is thus taking an unlawful bribe. The Prophet (peace be upon him) cursed the person who gives bribe or takes it. Bribery is a grievous crime and one of the grave major sins. It is ill-gains and unlawful for a Muslim to take for any reason.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.