Here, one important thing should be noted that taking zakat is not an insult, rather zakat is that purest part of money that is taken and given in the name of ALLAH as an obligation.
1: zakat cannot be given to a person who owns 7.5 tola gold and 52.5 of silver or the equivalent wealth. A person who owns house hold items like carpets and utensils, etc that are under possession and are not being used, then these items come under accumulation of wealth then such a person does not deserve zakat. Even if given zakat, that will serve the obligation.
2: zakat cannot be given to non-muslims.
3: zakat cannot be given to mother, father, maternal and paternal grandparents, or great grandparents, to off springs, to grand or great grand children, husband to wife or wife to husband. Other than them, zakat can be given to other relative, such as brothers, sisters, cousins, nieces, nephews etc.
4: zakat cannot be given to sayeds, i.e. to the descendents of Prophet Muhammad s.a.w.w from His daughter Fatima r.a. and His uncle Abbas. But only the genuine sayed, and not every person is sayed who claims to be so.
5: zakat cannot be given as a payment of services.
6: zakat cannot be paid for building, repairing or renovation of mosques because mosque is a woship place and called place of ALLAH.
7: a person cannot use zakat for burial and such expenses but if the heirs of the dead as poor, they can take zakat and can use it for the same purpose.
8: zakat money cannot be used to pay the outstanding debts of a person who died. If paid, such action will be considered invalid.