Dr. Monzer Kahf, a prominent economist and counsellor states: A last will is a document whose main purpose is to deal with the estate (money and property). If one lives in a country that has Islamic law of inheritance such as almost all Muslim countries, a last will’s meaning becomes restricted to distributing a maximum of one third of the net estate to charities and persons who are not heirs by law (these laws are derived from the Shari’ah). If a person lives in a country that has no Islamic inheritance law but allows to make a last will and distribute by wish of the person, the last will role becomes two folds: a) distribute the estate according to Shari’ah; and, b) distribute one third as a maximum for charities and non-heirs. Of course in both cases, a last will is useful to specify any debts that may be due on or to the person.
Writing a last will for issues that do not relate to estate distribution is not usual although many people do it. What is more common is when one make a last will for the estate, one includes such issues as who will take care of minors.