15 June 2026 was the due date for the first advance tax instalment for Tax Year 2026-27, a minimum of 15 percent of estimated tax liability. This is what actually happens if it has been missed, and what to do about it.

The Instalment Is Not Lost. The Interest Clock Starts.

Missing the deadline does not mean the instalment disappears or becomes a separate penalty. A shortfall now exists against the cumulative 15 percent requirement, and it begins accruing interest under Section 425 of the Income-tax Act, 2025, corresponding to the old Section 234C.

How the Interest Is Calculated

  • Interest is charged at 1 percent for every month, or part of a month, on the shortfall. Because any part of a month is treated as a full month, missing the 15 June date even by a single day attracts a full month's interest.
  • If paid along with the September instalment, interest runs for three months, June to August, on the unpaid amount.
  • On a shortfall of Rs 50,000, three months at 1 percent per month works out to Rs 1,500, the cost of waiting until September rather than paying now.

What To Do Now

  • Paying the missed amount immediately, even a few days late, stops the clock earlier than waiting until September. Interest is calculated in whole-month blocks, so part-month delays still count as a full month.
  • If the income estimate has changed, this is the point to revise it. The September instalment requires 45 percent cumulative, recalculated based on updated information.
  • Taxpayers under presumptive taxation, Section 58 of the Income-tax Act, 2025, are unaffected. Their advance tax is a single instalment due 15 March 2027.

What Does Not Happen

  • No separate penalty notice is issued for missing one instalment. The consequence is purely interest-based under Sections 424 and 425, applied at the time of assessment.
  • A missed June instalment does not by itself trigger scrutiny. It surfaces only in the interest computation when the return is processed.

Before You Wait Until September

A missed first instalment is a cost, not a crisis. It is quantifiable, 1 percent for every month or part of a month on the shortfall, and the sooner it is paid the fewer whole months it runs. Because a part-month counts as a full month, clearing the shortfall as soon as possible, rather than waiting for September, can save a full month's interest.