When can a Muslim wife relinquish her 'Mehr'?

A Muslim wife may remit her dower in whole or in part, but the remission must be made freely by a wife who has attained majority under the Indian Majority Act, 1875, that is, one "not less than 18 years of age"; a minor wife cannot validly remit it even after puberty (Abi Dhunimsa Bibi v. Muhammad Fathiuddin, Madras High Court). Puberty is relevant to capacity to marry, not to release a debt, and twenty-one is not the age of majority for this purpose.