A Muslim Will (Wasiyyah) is a testamentary document regulated by the Islamic Personal Law of inheritance. The Testator making such Will must have been a subject of Islamic law during his lifetime.
Ordinarily, in Islam, a Muslim has no right to share his/her property among his offspring or relatives by his own whim. The Islamic way of bequeathing inheritance has been divinely spelt out clearly in the Qur’an. Consequently, under a Muslim Will, a Testator cannot bequeath more than one-third of his property to beneficiaries who are not his legal heirs.
Furthermore, as regards the calculation of each beneficiaries’ share in the inheritance, the basic principles are that the closest relatives (legal heirs) must always inherit a share and must always have precedence over more distant relatives.
Beneficiaries under a Muslim Will can be Muslims or Non-Muslims so long as they are not hostile towards Islam. An institution may also be a valid beneficiary under a Muslim Will so long as it is not hostile towards Islam nor does it promote anti-Islamic activities. A person who renounces Islam cannot be a beneficiary under a Muslim Will.