My grandfather has been a farmer and his sons (including my father) have worked for the state government individualy. My grandfather did not make enough to file income tax and his sons each filed income tax as an individual. Until marriage the sons lived with the grandfather, but after that they lived seperately. That is, they had never lived jointly under one roof after marriage.
However about 40 years ago, my grandfather and his sons got togeather and signed a registered deed that they are living as Hindu Undivided Family (HUF) and all money/property earned by each has to be pooled in to the HUF. This never happened in practice.
Are we a Hindu Undivided Family, by virtue of just signing the deed?