A Will can be altered by the testator at any time before his or her death.
They can do so using a document called a codicil. A codicil is a document explaining, altering or adding to a will and which is considered as being part of the will. The formalities of writing the codicil are the same as for writing a will.
A codicil is an annex to a will. A codicil is made for the purpose of adding to, varying or revoking the provisions of an existing will.
A codicil puts into effect a change in an existing Will without requiring that the Will be re-executed. It is an extension to the actual will it is referring to.The same formalities that are necessary for the valid execution of a will must be observed when a codicil is executed. Failure to do so renders the codicil void.
A codicil without two witnesses is invalid.