Advance Tax Deadline Today: What Will Be the Consequences If You Miss September 15, 2026 Due Date?

Advance Tax Deadline Today: September 15, 2026

September 15, 2026 is an important tax deadline for individuals, professionals, businesses and other taxpayers who are liable to pay advance tax for the financial year 2026-27.

The September instalment is the second advance tax payment of the financial year. By this date, taxpayers generally need to have paid at least 45% of their estimated annual advance tax liability on a cumulative basis.

Advance tax follows a "pay as you earn" approach, allowing taxpayers to pay their estimated tax liability in instalments instead of waiting until the end of the financial year.

Who Has to Pay Advance Tax?

Advance tax generally applies when a taxpayer's estimated tax liability for the financial year, after considering applicable tax deducted or collected at source, is Rs 10,000 or more.

This can affect taxpayers earning income from sources such as:

• Salary where TDS does not fully cover the tax liability

• Business or professional income

• Interest income

• Rental income

• Capital gains

• Dividend income

• Other taxable income

However, certain taxpayers are exempt from advance-tax requirements. For example, a resident senior citizen who does not have income from a business or profession generally does not have to pay advance tax.

How Much Advance Tax Has to Be Paid by September 15?

Advance tax is normally paid in four stages during the financial year.

Due DateCumulative Advance Tax RequirementJune 15, 202615%September 15, 202645%December 15, 202675%March 15, 2027100%

Therefore, the September 15 deadline does not normally mean that a taxpayer has to pay another 45% on that date. Instead, the taxpayer's cumulative advance tax payment should reach 45% of the estimated annual liability.

For example, if the estimated advance tax liability for FY 2026-27 is Rs 2 lakh and Rs 30,000 was paid in June, the cumulative requirement by September 15 is Rs 90,000. The taxpayer would therefore need to pay another Rs 60,000 by September 15.

What Happens If You Miss the September 15 Deadline?

Missing the advance tax deadline does not generally mean that the entire tax liability becomes immediately payable as a separate penalty.

However, a taxpayer can face interest for deferment or short payment of advance tax under the applicable provisions.

The interest can increase the final tax outgo, particularly if the shortfall continues until later instalments or the end of the financial year.

Therefore, taxpayers who realise that they have missed the September 15 instalment should calculate the shortfall and pay the outstanding advance tax as soon as possible rather than waiting for the next deadline.

Section 234C: Interest for Deferment of Advance Tax

Interest for deferment of advance tax is generally associated with Section 234C.

The provision can apply when the required cumulative advance tax payment has not been made by the prescribed instalment dates.

Interest is generally calculated at 1% per month or part of a month on the applicable shortfall, subject to the conditions prescribed under the law.

This means that delaying the September payment can increase the interest burden, although the exact amount depends on the taxpayer's total tax liability, payments already made and the nature and timing of the shortfall.

Section 234B: Interest for Short Payment of Advance Tax

Another important provision is Section 234B, which deals with interest where there is a shortfall in advance tax payment in specified circumstances.

Section 234B can become relevant when the advance tax paid during the financial year is insufficient compared with the final tax liability.

The final amount of interest depends on the tax payable after considering advance tax, TDS and other applicable credits.

Therefore, taxpayers should not look only at the September 15 instalment in isolation. Their total advance tax position should be reviewed throughout the year.

What If Your Income Increased Suddenly?

Not all income can be predicted accurately at the beginning of the financial year.

For example, a taxpayer may receive an unexpected capital gain, large interest income, dividend income, professional fees or business income during the year.

Taxpayers should revise their estimated tax liability when their income changes and adjust subsequent advance tax payments accordingly.

The rules also provide special treatment for certain income such as capital gains. Where income arises after the relevant instalment date, advance tax can be paid in subsequent instalments after the income is received or arises, subject to the applicable provisions.

What Should You Do If You Missed September 15?

If you were required to pay advance tax but missed the September 15 deadline, the practical approach is to:

1. Calculate your estimated total tax liability for FY 2026-27.

2. Deduct TDS, TCS and advance tax already paid.

3. Calculate the advance tax shortfall.

4. Pay the required amount as soon as possible.

5. Recalculate your tax position before the December 15 and March 15 instalments.

6. Keep records of all tax payments and challans.

Paying the tax promptly can prevent the shortfall from continuing unnecessarily.

Advance Tax Deadlines After September 15

The next major advance tax deadline is December 15, 2026.

By December 15, taxpayers generally need to have paid at least 75% of their estimated annual advance tax liability cumulatively.

The final instalment is due on March 15, 2027, by which cumulative advance tax payments should generally reach 100%.

Businesses and professionals should therefore regularly update their income and expense estimates instead of calculating advance tax only once a year.

Is There a Penalty for Missing Advance Tax?

The immediate financial consequence of missing or underpaying an advance tax instalment is generally interest rather than a separate fixed late-payment penalty.

Sections 234B and 234C can increase the interest burden depending on the nature of the shortfall and the taxpayer's overall tax position.

This is different from a late fee for filing an income tax return. Advance tax and ITR filing are separate compliance requirements.

Key Takeaways

• September 15, 2026 is the second advance tax instalment deadline for FY 2026-27.

• Eligible taxpayers generally need 45% of their estimated annual advance tax paid cumulatively by this date.

• The advance tax requirement generally applies when net tax liability is Rs 10,000 or more, subject to applicable exemptions.

• Missing or underpaying the instalment can result in interest under Section 234C.

• Section 234B may also become relevant where there is an overall shortfall in advance tax.

• Interest can increase the taxpayer's final tax burden.

• Taxpayers with changing income should update their estimates and make appropriate subsequent payments.

• The next major deadlines are December 15, 2026 and March 15, 2027.

Conclusion

The September 15, 2026 advance tax deadline is important for taxpayers whose estimated tax liability requires them to pay advance tax during FY 2026-27. By September 15, the cumulative payment should generally reach 45% of the estimated annual liability.

Missing the deadline does not necessarily result in a fixed penalty, but a shortfall can trigger interest and increase the taxpayer's overall tax cost. Taxpayers who have missed the deadline should therefore review their tax liability and make the required payment as soon as possible rather than waiting until the next instalment.

The exact interest liability depends on individual circumstances, including tax already paid through TDS/TCS and previous advance tax instalments.