You may wish to add or revoke a gift under your will for one the following reasons:
If you want to make one or two fairly simple changes to your will, or perhaps you wish to change an executor or guardian, a quick and convenient option is to use a codicil. A codicil is a document that amends an existing will, but does not replace it. It allows you to change your will without making an entirely new will, and must be signed in the exact same way as the will was signed (although the two witnesses do not have to be the same two people that witnessed the original will). It is recommended that the codicil mentions the date of your current will so that it is clear that the codicil should be read in conjunction with it. If a will is altered by codicil, that codicil should be kept with the original will.
A codicil is appropriate if you only want to make one or two fairly straightforward changes to your will. If you plan to amend more than three legacies, it is advisable to create a new will.
A will may be amended by more than one codicil. However, the more codicils there are, obviously the more complicated it becomes to keep track of their effects. Each subsequent codicil should refer explicitly to the original will and all previous codicils, and they should all be kept together. If there are more than a small number of codicils, or it starts to look complicated – then it is time to make a new will.