New Delhi, Oct. 6 -- A will may be legally valid and yet fail to dispose of the entire estate. That distinction matters because a valid will is not necessarily a complete will.

Specific gifts often receive most of the attention in estate planning: a house to one beneficiary, investments to another, money in a particular account to someone else. But those bequests deal only with the assets expressly covered by them.

Years later, the house may have been sold, the bank account closed, and the testator may have acquired new investments, shares or other assets.

The will may remain perfectly valid. The difficulty is that those newly acquired assets may not have been specifically dealt with. Unless the will contains an effective residuary pro...