Muslim law of succession constitutes four sources of Islamic law:

1. The Holy Quran
2. The Sunna - that is, the practice of the Prophet
3. The Ijma - that is, the consensus of the learned men of the community on what should be the decision on a particular point
4. The Qiya - that is, an analogical deduction of what is right and just in accordance with the good principles laid down by God.

Muslim law recognizes two types of heirs, Sharers and Residuaries. Sharers are the ones who are entitled to a certain share in the deceased's property and Residuaries would take up the share in the property that is left over after the sharers have taken their part.

Sharers:

The Sharers are 12 in number and are as follows: (1) Husband, (2) Wife, (3) Daughter, (4) Daughter of a son (or son's son or son's son and so on), (5) Father, (6) Paternal Grandfather, (7) Mother, (8) Grandmother on the male line, (9) Full sister (10) Consanguine sister (11) Uterine sister, and (12) Uterine brother.

The share taken by each sharer will vary in certain conditions. For instance, a wife takes 1/4th of share in a case where the couple is without lineal descendants, and a one-eighth share otherwise. A husband (in the case of succession to the wife's estate) takes a half share in a case where the couple is without lineal descendants, and a one-fourth share otherwise. A sole daughter takes a half share. Where the deceased has left behind more than one daughter, all daughters jointly take two-thirds.

If the deceased had left behind son(s) and daughter(s), then, the daughters cease to be sharers and become residuaries instead, with the residue being so distributed as to ensure that each son gets double of what each daughter gets.

Non-Testamentary and Testamentary succession under Muslim law:
In Non-testamentary succession, the Muslim Personal Law (Shariat) Application Act, 1937 gets applied. On the other hand, in case of a person who dies testate i.e. one who has created his will before death, the inheritance is governed under the relevant Muslim Shariat Law as applicable to the Shias and the Sunnis.

In cases where the subject matter of property is an immovable property, situated in the state of West Bengal, Chennai and Bombay, the Muslims shall be bound by the Indian Succession Act, 1925. This exception is only for the purposes of testamentary succession.

Birthright:

Inheritance of property in Muslim law comes only after the death of a person, any child born into a Muslim family does not get his right to property on his birth. If an heir lives even after the death of the ancestor, he becomes a legal heir and is therefore entitled to a share in the property. However, if the apparent heir does not survive his ancestor, then no such right of inheritance or share in the property shall exist.

Distribution of the Property:

Under the Muslim law, distribution of property can be made in two ways per capita or per strip distribution. The per capita distribution method is majorly used in the Sunni law. According to this method, the estate left over by the ancestors gets equally distributed among the heirs. Therefore, the share of each person depends on the number of heirs. The per strip distribution method is recognised in the Shia law. According to this method of property inheritance, the property gets distributed among the heirs according to the strip they belong to. Hence the quantum of their inheritance also depends upon the branch and the number of persons that belong to the branch.

Rights of females:

Muslim does not create any distinction between the rights of men and women. On the death of their ancestor, nothing can prevent both girl and boy child to become the legal heirs of inheritable property. However, it is generally found that the quantum of the share of a female heir is half of that of the male heirs. The reason behind this is that under the Muslim law a female shall upon marriage receive mehr and maintenance from her husband whereas males will have only the property of the ancestors for inheritance. Also, males have the duty of maintaining their wife and children.

Widow's right to succession:

Under Muslim law, no widow is excluded from the succession. A childless Muslim widow is entitled to one-fourth of the property of the deceased husband, after meeting his funeral and legal expenses and debts. However, a widow who has children or grandchildren is entitled to one-eighth of the deceased husband's property. If a Muslim man marries during an illness and subsequently dies of that medical condition without brief recovery or consummating the marriage, his widow has no right of inheritance. But if her ailing husband divorces her and afterwards, he dies from that illness, the widow's right to a share of inheritance continues until she remarries.

A Child in the Womb:

A child in the womb of its mother is competent to inherit provided it is born alive. A child in the embryo is regarded as a living person and, as such, the property vests immediately in that child. But, if such a child in the womb is not born alive, the share already vested in it is divested and, it is presumed as if there was no such heir (in the womb) at all.

Escheat:

Where a deceased Muslim has no legal heir under Muslim law, his properties are inherited by Government through the process of escheat.
Marriage under the Special Marriage Act, 1954:

Where a Muslim contracts his marriage under the Special Marriage Act, 1954, he ceases to be a Muslim for purposes of inheritance. Accordingly, after the death of such a Muslim his (or her) properties do not devolve under Muslim law of inheritance. The inheritance of the properties of such Muslims is governed by the provisions of the Indian Succession Act, 1925 and Muslim law of inheritance is not applicable.