The deduction for set investments and payments, up to one shared ceiling a year, under the old regime.
Section 123 (formerly 80C) lets you deduct up to ₹1,50,000 a year for payments such as your own PF contribution, PPF, ELSS funds, life insurance premiums, the principal of a home loan, tuition fees and five-year tax-saving deposits. They all share the one ceiling.
It exists only under the old regime; the new regime gives up Chapter VI-A deductions in exchange for lower slab rates. Your own NPS contribution can count here too, but it also has a separate allowance, Section 124 (formerly 80CCD(1B)), on top.
Figures on this page are filled from the same tax and scheme tables the calculators use, for the current financial year. Every term in the glossary.