Power of attorney is required when you want to sell share from your Demat account and the shares will go out of your Demat account. Here you can know what is power of attorney, is Poa mandatory for Demat account opening, Zerodha POA, Upstox POA, stock market beginners. https://demataccountopen.com/what-is-power-of-attorney-poa-and-is-it-mandatory/