Five adjustments produce the overwhelming majority of s.143(1) demands from the Income-tax Act, 1961: TDS credit denied on a 26AS/AIS mismatch, 234B interest added for an advance-tax shortfall, a carried-forward loss disallowed because the return was filed late (s.80), rounding differences, and an 80C/80D deduction disallowed because it did not reconcile with the Form 16 data the CPC holds. Each code has a specific cause and a specific remedy — and the right remedy depends on whether the error is yours or the CPC's. Decode the adjustment first; pay second.

The five common adjustments — cause and remedy

The intimation displays each adjustment with a description in the "adjustment details" section. The labels below describe the adjustments by their substance; the exact code strings shown on your intimation may differ. on the current code format for your assessment year.

Adjustment	What CPC did	Why	Remedy
TDS credit denied	Reduced your TDS credit	Claimed credit not matching 26AS/AIS (late posting, wrong PAN, wrong section)	Check 26AS; raise AIS feedback for wrong entries; chase the deductor's correction; file s.154 rectification if the credit posted later
234B interest added	Added advance-tax interest	Your total tax after TDS exceeded ₹10,000 and advance tax was short	Verify advance-tax payments; if paid, file s.154 with the challans; if genuinely short, the interest is correct
Loss carry-forward disallowed	Denied a brought-forward loss	Return filed after the due date — s.80 bars carry-forward of losses	Check the filing date; if filed late, the bar is statutory — the loss is lost
Rounding adjustment	Adjusted the tax by a few rupees	Rounding of the tax liability (s.288B)	Typically ₹0–₹100; pay it or ignore only if trivial — but clear it so the demand closes
80C/80D disallowed	Denied a deduction	Claimed deduction not reconciling with the data CPC holds (employer Form 16 not updated, or claim above the statutory cap)	Verify the proof (policy, PPF statement); if correct, file s.154 with the evidence; if genuinely ineligible, the denial is right

TDS denied: the most common, and the most fixable

A TDS mismatch is usually not a wrong claim at all — it is a timing or data gap. The credit you claimed exists, but the department's ledger does not yet show it. Before you do anything:

Open Form 26AS and the AIS; find the specific TDS line.
Check whether it is a late posting (deductor filed the TDS statement after you filed) — the most common cause.
Check the PAN and section code — a wrong PAN or a wrong section (e.g., 194S filed under 194-IA) blocks the credit.
If the entry is genuinely not yours, raise AIS feedback marking it incorrect.
If the credit is yours but posted late, file a rectification u/s 154 after it appears.

The AIS is informational; the credit that counts is what 26AS shows. Claim only what reconciles, and document the rest.

234B interest: verify before you pay

Section 234B charges 1% per month (or part) on the shortfall from 1 April of the assessment year if your advance tax fell below 90% of the assessed tax. It is correct in two situations — you skipped advance tax, or your self-assessment was too low. It is wrong in one: you did pay advance tax and the CPC did not credit it. If you have the challans, that is a s.154 rectification, not a payment.

Loss carry-forward disallowed: the one you cannot fix

If the return was filed after the due date under s.139(1), s.80 bars the carry-forward of losses — business, capital, and other-source losses are all lost. There is no remedy at the 143(1) stage for a late-filed return; the loss is statutory. The adjustment is only avoidable by filing on time, which makes the AY 2026-27 due date (31 July 2027, or the extended date) the controlling deadline for anyone with a loss to carry.

Changed FY 2025-26: No change to the s.143(1) adjustment categories this year. What changed is data reach — AIS and SFT information now feeds more adjustments automatically, so TDS-mismatch and deduction-denial lines are driven by the same third-party data you can see on the portal. Check it before you respond.

Worked example: Sarika's three-line intimation

Persona: Sarika, salaried, files ITR-1 for AY 2026-27. Her intimation shows three adjustments:

TDS denied — ₹6,000. She claimed ₹1,26,000 TDS; 26AS shows ₹1,20,000. Cause: her employer's March-quarter TDS posted after she filed.
234B interest — ₹1,120. Computed on a ₹80,000 shortfall in self-assessment.
Rounding — ₹2. Trivial.

Step 1 — TDS line. Sarika opens 26AS, finds the ₹6,000 posted in May. It is hers. She files a rectification u/s 154 with the 26AS extract; the ₹6,000 credit is restored.

Step 2 — 234B line. She checks her bank challans. She actually paid ₹90,000 as advance tax in March — the full ₹80,000 shortfall plus more — but the CPC applied only part of it. She attaches the challan to the same rectification. The ₹1,120 is re-computed.

Step 3 — Rounding. The ₹2 she pays; it closes the demand.

Net result: the ₹6,000 TDS is restored and the 234B is reduced — a ₹7,120 swing fixed by one s.154 rectification, not by paying the demand as raised. on the evidence the CPC requires for a s.154 TDS restoration.

Frequently asked questions

1. Why was my TDS credit denied in 143(1)?

Because the claimed amount did not match 26AS/AIS — usually a late posting, wrong PAN, or wrong section code. Check 26AS first; the credit may simply have posted after you filed.

2. What is 234B interest and why was it added?

Interest at 1% per month on the advance-tax shortfall from 1 April of the assessment year, added when your advance tax fell below 90% of the assessed tax.

3. Can a carried-forward loss be restored after 143(1)?

No, if the return was filed late. Section 80 bars loss carry-forward for late returns; the disallowance at 143(1) is statutory and cannot be rectified.

4. My 80D deduction was disallowed but I have the policy — what do I do?

File a rectification u/s 154 with the evidence (policy, premium receipt). If the deduction is correct, the CPC should restore it; if the claim was genuinely ineligible, the denial stands.

5. Do I pay a ₹2 rounding difference?

Pay it — the amount is trivial, but an open demand line attracts s.220(2) interest if left. Clear it in the response window.

6. What is the fastest way to fix a CPC error in a 143(1)?

File a rectification u/s 154 on the e-filing portal with the supporting document (26AS extract, challan, policy proof). It is faster and cheaper than an appeal.

7. Where do I see the adjustment reasons?

In the intimation itself — the "adjustment details" section, and in your AIS/26AS on the portal. Download both before responding.

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Last verified: 2026-08-08 (FY 2025-26 / AY 2026-27)

Sources: s.143(1)(a), s.234B (advance-tax interest), s.80 (loss carry-forward bar), s.154 (rectification), s.199/203AA (TDS credit and 26AS), s.288B (rounding), s.220(2) (interest on unpaid demand), Income-tax Act, 1961. Adjustment-code display format flagged for CA verification. For a personalised read, use the Notice Explainer.

Topics:CPC adjustment143(1)TDS mismatch234Brounding

Go deeper with our hub guides

Statute-cited, section-by-section guides covering the same ground this article does.

ROCROC Annual FilingMGT-7/MGT-7A, AOC-4, DIR-3 KYC, s.403 late fees, and the strike-off risk of missing two consecutive years.Open the guide →Advance TaxAdvance TaxS.208–211 instalment schedule, s.234B/234C interest on shortfall, and the 44AD single-instalment rule — statute-cited.Open the guide →

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