From ITR to PAN-Aadhaar linking: Key important December tax and personal finance deadlines

The month of December has begun with a significant line-up of financial events and deadlines that can affect individuals in several ways. From income tax return (ITR) to PAN-Aadhaar linking deadlines, the last month of the year brings many crucial compliance events to look out for.

ITR filing deadline for tax audit cases

The ITR filing deadline for tax audit cases, which was extended by the Central Board of Direct Taxes (CBDT), is December 10, 2025. Previously, the deadline was October 31, 2025.

When a taxpayer is required to have their accounts audited by a Chartered Accountant (CA) and file a specific audit report, the ITR filing is governed by the tax audit deadline. This year, the deadline was extended to help taxpayers file their returns on time with changes in the ITR forms.

Advance tax deadline

The advance tax deadlines left for this financial year (FY25) are December 15, 2025 and March 15, 2026.

Advance tax is an income tax paid in installments throughout the financial year, instead of paying in a lump sum at the end of the year. This system is for individuals whose estimated tax liability exceeds ₹10,000 during the financial year. It helps taxpayers pay as they earn and ensures a steady flow of revenue for the government.

Individuals who are required to pay advance tax must pay the third instalment by December 15, 2025.

PAN-Aadhaar linking

Individuals who got their Aadhaar on or before October 1, 2024, have to link their PAN and Aadhaar by December 31, 2025. If you miss this deadline, your PAN will become inoperative and affect your key financial transactions.

PAN is an important identifier in India, mandatory for financial and tax-related activities, including opening bank accounts, filing income tax returns and making investments. Remember to complete your PAN-Aadhaar linking before the year ends to avoid complications.

Belated and revised ITR filing deadline

If a taxpayer missed filing an income tax return (ITR) for the financial year 2024-25 (FY25), a belated ITR can be filed before December 31, 2025. While taxpayers will still have to pay a fee on belated returns, they can prevent further penalties or notices from the IT department if they file the return before this calendar year ends.

The penalty for a belated ITR, under Section 234F, is ₹5,000 for those with an annual income above ₹5 lakh and ₹1,000 for those with an annual income below ₹5 lakh. Importantly, taxpayers can claim refunds through belated returns, but remember that the tax regime cannot be changed after the deadline (which was September 16 this year) passes.

Moreover, if you did file your ITR before the deadline but made a mistake, omitted any detail or entered inaccurate information, you can file a revised return by December 31, 2025. If you think you made a mistake but aren’t sure, make sure you check your ITR carefully and verify all details.

It’s important to correct any errors, such as a mismatch between your ITR and AIS/TIS, reporting incorrect capital gains, or claiming a deduction incorrectly, because you can receive a notice from the income tax department regarding the same.

To avoid notices and penalties, taxpayers should check their returns carefully and correct their mistakes (if any). There’s no penalty for filing a revised return before December 31, 2025. However, you will have to pay interest on the unpaid tax if any additional tax liability arises, which will be applicable from the due date until you file the revised return and make the payment.

Portfolio clean-up

December is a great time to clean and declutter your investment portfolio and start the new year with clear financial goals. Before the year ends, review underperforming funds, check for portfolio overlap and rebalance your asset allocation.

A year-end clean-up will help you manage your money efficiently and eliminate investments that aren't adding value to your long-term objectives.

Tax planning for FY26

Early planning can help you file accurately and on time, and can save you from unexpected trouble later. Treat your ITR filing as an ongoing activity, and manage your finances responsibly.

Insurance planning

Every year, individuals should review their insurance policies and check if they are adequately covered. If you don't own a policy yet, this is the right time to buy one. It's crucial to have your insurance sorted out to prevent any financial trouble during emergencies.

Before the year ends, ensure all pending premiums are paid to prevent any policy lapses, and review your overall financial health and goals to begin the new year with peace of mind.

Two important deadlines, for submitting a Life Certificate (Jeevan Pramaan Patra) and switching from NPS to UPS, have passed. Both deadlines were November 30, 2025, and were crucial for pensioners and government employees.

Meanwhile, the State Bank of India has discontinued its mCASH service from November 30, 2025. Now, SBI customers will not be able to send money without beneficiary registration or claim payments through the mCASH link. The bank has advised customers to use secure options like UPI, IMPS, NEFT and RTGS.

Notably, there are several important financial events this month, including the Reserve Bank of India’s Monetary Policy Committee Meeting on December 3-5.