Kasudheer-Your wife is the first legal heir for your all assets. So nomination is enough. Do remember that nominee can just act as a trustee but not claim ownership of the asset. However, in your case wife is nominee who is the first legal heir. So it is enough. WILL is required when there is a complication of to whom you want to assign the assets (as against the rules of succession act). In my view, for your MF investments nomination is enough.