There is a misconception that Islamic inheritance law is misaligned with legal laws, including attorney, lawyer, and orientalist. However, at the core, there are drastic similarities between legal and Muslim succession law regarding estate planning. Muslim inheritance primary heirs (spouse and children) are similar to legal or secular laws. These fixed heirs cannot be disinherited as per Islamic law. Let us examine the following similarities in Islamic inheritance laws vs. legal laws.
Islamic law favors creditors for debt payments upon death. Instead, creditors have more upper hand in Islam compared to Legal laws. People can find a way to circumvent the debt through illegal estate planning, but all that is not allowed under Islamic law. We should appreciate the laws of Islam that allow a believer to pay off debts and purify his or her sins before departure.
There is a definite share of spouse and children under Islamic law (i.e., forced heirship). Not all legal laws favor the voluntary or mandatorily inheritance share between spouse and children in secular and nuclear family settings. Islamic laws allow the share of Spouse and Children as a priority. No other inheritors can block Spouse and Children (principally) from taking inheritance under Islamic law.
Islamic law allows one-third Testamentary bequest part of your Wills or Trust. There are no legal restrictions, except you need an estate plan that does not compromise tax efficiency.
Everyone needs an estate plan (i.e., Wills or Trust) to protect their values, wishes, belief, and inheritors under Islamic law (read here why). No country's laws restrict expressing individual wishes; instead, the constitution promises the inheritance of every individual in the country.
Islamic law allows the share of inheritance for more than 25 generations if primary heirs (i.e., Spouses, children, parents, etc.) do not survive and meet other necessary Islamic law rulings. Legal laws are very specific and largely differ (from one country or jurisdiction to another) on who can be eligible to receive a share if the primary heirs do not survive, but in general, they allow succession for the extended family if primary heirs (Spouse, Children, etc.,) do not survive. However, most secular estate plans (i.e., Wills or Trusts) are limited to Spouse and Children.
Allah, the Most Glorified and the Most High, knows the best. As a human, We are limited to everything and can not perceive it in totality...