Do I have to pay tax when I sell my house?

If you have held the flat long enough to be long-term, the gain is taxed as long-term capital gains (currently 12.5% plus surcharge and cess for transfers on/after 23 July 2024). But you can often reduce or eliminate the tax by reinvesting — into another residential house, or into specified capital-gains bonds within the prescribed time. Plan the reinvestment before you sell, and keep proof of your purchase cost and improvement expenses.