A client called me last week in mild panic. He'd paid ₹4.2 lakh in advance tax, but selected AY 2027-28 instead of AY 2026-27 by mistake. His first question was, "Do I need to pay it again and claim a refund later?" No — but he did need to move fast, because these corrections run on a clock.

Challan mistakes are more common than they should be — wrong Assessment Year, wrong Major Head (Income Tax vs Corporation Tax), wrong Minor Head (Advance Tax marked as Self-Assessment Tax, or vice versa). Left uncorrected, these errors can mean your tax credit doesn't show up in your Form 26AS or AIS, notices asking why tax "wasn't paid," or a mismatch that delays your refund. This guide tells you exactly who can fix what, and how fast you need to move.

What You Can Correct Yourself on the e-Filing Portal

The Income Tax Department's e-Filing portal now has a self-service "Challan Correction Request" feature under Services > Challan Correction. It covers three specific corrections, but only for challans paid under Minor Heads 100 (Advance Tax), 300 (Self-Assessment Tax) and 400 (Regular Assessment Tax), and their corresponding Major Heads.

Practical implication: If you spot the error within a week, you have the widest set of options — you can still fix the year itself. Miss that 7-day window and the AY is locked from online correction; you'll need to approach your Jurisdictional Assessing Officer even though the Major or Minor Head correction window (30 days) may still be technically open for other fields on the same challan.

The "Unconsumed Challan" Condition That Trips People Up

Online correction only works if the challan is unconsumed — meaning it hasn't yet been adjusted against any tax liability or pulled into a processed return. The moment your challan gets consumed (typically once your ITR is processed and the tax credit is matched), the online correction door closes.

This is the part clients usually miss. If you've already filed your return referencing that challan, don't wait — file the correction request before you file the ITR, not after. Once the CPC processes your return, the online option is gone and you're back to writing to the AO.

How the Online Correction Actually Works

1. Log in to the e-Filing portal and go to Services > Challan Correction > Create Challan Correction Request.
2. Select the challan using either the Challan Identification Number (CIN) or the relevant Assessment Year/Tax Year — only unconsumed challans will show up.
3. Choose which attribute you're correcting: AY/Tax Year, Major Head, or Minor Head. You can select more than one in a single request.
4. Enter the correct values and review the before-and-after summary.
5. e-Verify using Aadhaar OTP, DSC, EVC through net banking, or Demat account.

Processing generally takes a couple of weeks, though the Department hasn't officially committed to a fixed turnaround — if there's an unusual delay, raising a grievance on the portal is your recourse. One important restriction: a challan can only be corrected once through the portal. If you discover a second error later, that one goes straight to the AO.

Where the Income Tax Act, 2025 Changes the Picture

Since 1 April 2026, challans are generated on a Tax Year (TY) basis under the Income Tax Act, 2025, replacing the Assessment Year basis used under the 1961 Act. If your original challan was created under the 1961 Act framework (AY-based, for periods up to AY 2026-27), the correction screen will let you switch within the AY/TY framework as applicable — but you should still cite the Act under which the original challan was paid when you write to your CA or the AO, to avoid confusion in the correspondence trail. If your practice still deals with older AY-based challans alongside newer TY-based ones, keep the two threads separate in your own records; mixing references is exactly the kind of thing that slows down manual correction requests with the AO.

When You Must Go to the Jurisdictional Assessing Officer

There's no way around the AO for:

• PAN or TAN corrections — never available online, regardless of how recent the challan is.
• TDS/TCS challans — these route through TRACES, not the e-Filing portal's challan correction service.
• Minor Heads outside 100/300/400 — including block assessment challans under certain heads.
• Consumed challans, or challans where the online correction window has lapsed.
• A second correction on a challan already corrected once online.

When you do approach the AO, carry the original challan copy, a covering letter clearly stating the error and the correct details, and any supporting proof of payment. There's no prescribed online form for AO-route corrections — it's a manual application, so response times vary by jurisdiction.

What To Do Right Now

If you've made a challan error, check the deposit date first — that determines which corrections are still open to you. If you're within 7 days, fix the AY immediately; the Major/Minor Head window gives you a bit more breathing room, but don't sit on it. And if your challan is already tied to a filed and processed return, stop trying the portal and write to your AO directly — you'll save yourself a rejected request and a few wasted days.

CA Praneeth Thunuguntla | Thunuguntla & Associates | Income Tax & GST Advisory