IT Declarations for Employees(As per 2020-21 Budget) Old ESS
Investment declaration must be done at the beginning of a financial year. Your employer asks you to declare your tax-saving investments for the year to enable tax deduction accordingly from your monthly salary.
At the beginning of the financial year, you have to just make an estimate of the investments that you intend to make. You don't need to submit actual proofs until the end of the financial year.