These Gifts are a Form of Bribery

Question :

I am a manager of a department; when people finish their dealings with me, some of them give me a gift, knowing that they cannot do without my services and knowing that they will come back to me in the future. Can I take their gifts with a good intention or are those gifts considered bribery and ill-gotten gains?

Answer:

You must not accept these gifts, because they come under the ruling of bribery and because you might in the future give those people precedence over others in dealings, either from a desire for more gifts or out of shyness. There are reports from the Sunnah of the Prophet that indicate that accepting this kind of a gift is not allowed.

You, and others in your position, should make your intention pure for Allah in your work; you should also be sincere to every customer, fulfilling their needs according to merit, not according to friendship, relation, or desire. Giving precedence to people for these wrong reasons leads to delaying others in their needs, and this is an infringement upon their rights. Allah Almighty says:
"Verily, Allak commands that you should render back the trusts to those whom they are due."

Allah Almighty says describing the successful ones:
"Those who are faithfully true to their trusts and to their covenants".

And with Allah is the facilitation to do what is right.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 8 Pages 147-148