If parties to a Hindu marriage are sapinda to each other, the marriage is

Section 5(v) of the Hindu Marriage Act, 1955 requires that the parties "are not sapindas of each other, unless the custom or usage governing each of them permits of a marriage between the two". Section 11 declares a marriage in contravention of clauses (i), (iv) and (v) of section 5 "null and void".

So, unless a custom permits it, a sapinda marriage is void from the start, not merely voidable; voidable marriages are those under section 12.