When pension security is not available, senior citizens typically rely on monthly interest income from fixed deposits (FDs). However, with the changes in income-tax rules this year in the Budget 2025, it is important to understand the tax treatment of interest income and plan accordingly. From financial year (FY) 2023-24, the government made the new tax regime the default choice. If one wants the old tax regime, one needs to specifically opt for it. From this year (FY2025-26), the income is tax-free up to Rs 12 lakh under the new regime, and the rebate under Section 87A of the Income-tax Act, 1961, is Rs 60,000, which was previously Rs 25,000.