A Codicil is defined under the Indian Succession Act as “an instrument made in relation to a Will and explaining, altering or adding to its disposition and shall be deemed to form part of the Will.”
A codicil must be executed similar to Will, being written and attested by two witnesses. If the Will is registered, then the codicil also needs to be registered. Like a Will, a codicil can be altered, added to and further explained by another codicil by proper execution and attestation by witnesses.
In most cases, it is easier to create a new Will rather than adding a codicil to an existing Will to avoid the confusion. If a codicil is created as an addendum or addition to an existing Will, it should be stored along with the Will with proper attestation.