In strict Legal terminology, annulment refers only to making a voidable marriage null; if the marriage is void ab initio, then it is automatically null, although a legal declaration of nullity is required to establish this.
The grounds for a marriage annulment may vary according to the different legal jurisdictions, but are generally limited to fraud, bigamy, blood relationship and mental incompetence including the following:
1) Either spouse was already married to someone else at the time of the marriage in question;
2) Either spouse was too young to be married, or too young without required court or parental consent. (In some cases, such a marriage is still valid if it continues well beyond the younger spouse's reaching marriageable age);
3) Either spouse was under the influence of drugs or alcohol at the time of the marriage;
4) Either spouse was mentally incompetent at the time of the marriage;
5) If the consent to the marriage was based on fraud or force;
6) Either spouse was physically incapable to be married (typically, chronically unable to have sexual intercourse) at the time of the marriage;
7) The marriage is prohibited by law due to the relationship between the parties. This is the "prohibited degree of consanguinity", or blood relationship between the parties. The most common legal relationship is 2nd cousins; the legality of such relationship between 1st cousins varies around the world.
8) Prisoners sentenced to a term of life imprisonment may not marry.
9) Concealment (e.g. one of the parties concealed a drug addiction, prior criminal record or having a sexually transmitted disease)
In Section 5 of the Hindu Marriage Act 1955, there are some conditions laid down for a Hindu Marriage which must be fulfilled in case of any marriage between two Hindus which can be solemnized in accordance with the requirements of this Act.
Section 5 Condition for a Hindu Marriage - A marriage may be solemnized between any two Hindus, if the following conditions are fulfilled, namely:
(i) Neither party has a spouse living at the time of the marriage;
(ii) At the time of the marriage, neither party,-
(a) is incapable of giving a valid consent of it in consequence of unsoundness of mind; or
(b) though capable of giving a valid consent has been suffering from mental disorder of such a kind or to such an extent as to be unfit for marriage and the procreation of children; or
(c) has been subject to recurrent attacks of insanity or epilepsy;
(iii) The bridegroom has completed the age of twenty one years and the bride the age of eighteen years at the time of the marriage;
(iv) The parties are not within the degrees of prohibited relationship unless the custom or usage governing each of them permits of a marriage between the two;
(v) The parties are not sapindas of each other, unless the custom or usage governing each of them permits of a marriage between the two:
An annulment may be granted when a marriage is automatically void under the law for public policy reasons or voidable by one party when certain requisite elements of the marriage contract were not present at the time of the marriage
A marriage is automatically void and is automatically annulled when it is prohibited by law. Section 11 of Hindu Marriage Act, 1955 deals with:
Interfamily Marriage. A marriage between an ancestor and a descendant, or between a brother and a sister, whether the relationship is by the half or the whole blood or by adoption.
A voidable marriage is one where an annulment is not automatic and must be sought by one of the parties. Generally, an annulment may be sought by one of the parties to a marriage if the intent to enter into the civil contract of marriage was not present at the time of the marriage, either due to mental illness, intoxication, duress or fraud
Voidable Marriages- (1) Any marriage solemnized, whether before or after the commencement of this Act, shall be voidable and may be annulled by a decree of nullity on any of the following grounds, namely:-
(a) that the marriage has not been consummated owing to the impotency of the respondent; or
(b) that the marriage is in contravention of the condition specified in clause (ii) of Section 5; or
(c) that the consent of the petitioner, or where the consent of the guardian in marriage of the petitioner was required under Section 5 as it stood immediately before the commencement of the Child Marriage Restraint (Amendment) Act, 1978, the consent of such guardian was obtained by force or by fraud as to the nature of the ceremony or as to any material fact or circumstance concerning the respondent; or
(d) that the respondent was at the time of the marriage pregnant by some person other than the petitioner.
(a) on the ground specified in clause (c) of sub-section (1) shall be entertained if-
(i) the petition is presented more than one year after the force had ceased to operate or, as the case may be, the fraud had been discovered ; or
(ii) the petitioner has, with his or her full consent, lived with the other party to the marriage as husband or wife after the force had ceased to operate or, as the case may be, the fraud had been discovered;
(i) that the petitioner was at the time of the marriage ignorant of the facts alleged;
(ii) that proceedings have been instituted in the case of a marriage solemnized before the commencement of this Act within one year of such commencement and in the case of marriages solemnized after such commencement within one year from the date of the marriage; and
(iii) that marital intercourse with the consent of the petitioner has not taken place since the discovery by the petitioner of the existence of the said ground.