Integrated Business Solutions (Multidisciplinary Case Study with Strategic Management) · Direct Tax Laws & International Taxation

Assessment, Procedures, TDS and Advance Tax for CA Final IBS

Updated 5 October 2026 · Fact-checked

This topic covers how tax is collected during the year (TDS, TCS, advance tax), how returns are filed, how the officer assesses or reassesses income, and how appeals, interest and penalties follow. Solve it by fixing the date, the amount and the rule, then computing interest month by month with simple interest.

Understand Assessment, Procedures, TDS and Advance Tax

Tax law has two halves. The first half is about substance: what is income and how much is taxable. The second half is about procedure: who pays, when, how it is checked and what happens if you are late or wrong. This topic is the second half. In an IBS case study it appears as a side issue inside a bigger business story.

Tax reaches the government in three ways before the final bill. TDS is deducted by the payer at source. TCS is collected by the seller at the time of sale. Advance tax is paid by the taxpayer in instalments during the year. All three are credited against the final tax. What remains is paid as self-assessment tax when the return is filed.

After the return is filed, the department may process it, scrutinise it, or reopen it. Assessment is the officer's determination of income and tax. Reassessment is allowed when income has escaped assessment, within time limits that get longer when the escaped amount is large. If you disagree with an order, you appeal: first to the Commissioner (Appeals), then to the Tribunal, then to the High Court on a substantial question of law.

Defaults cost money. Interest is compensation for late filing, short advance tax or late TDS. Penalty is punishment for conduct, such as under-reporting or misreporting income. Interest is computed by formula. Penalty depends on facts. Case studies test whether you can tell them apart.

Always use the rates, thresholds and section references from the Income-tax law applicable to your exam attempt, as given in the question or the rate chart. This page teaches the logic and the date mechanics, which stay stable even when rates change.

Key rules to remember

Advance tax instalments (non-presumptive taxpayers): By 15 June: 15% | by 15 Sept: 45% | by 15 Dec: 75% | by 15 March: 100% (all cumulative); Advance tax applies where the tax payable after TDS/TCS is ₹10,000 or more. Eligible presumptive taxpayers pay the full amount by 15 March.
Interest for late filing (234A): 1% × tax payable on total income (after TDS, TCS, advance tax) × months or part months of delay; Runs from the day after the due date to the date of filing. Part of a month counts as a full month. It is simple interest.
Interest for default in advance tax (234B): 1% × (assessed tax − TDS/TCS − advance tax paid) × months or part months; Applies only if advance tax paid is less than 90% of the assessed tax. Runs from 1 April after the end of the tax year to the date of payment or determination. Self-assessment tax paid reduces the shortfall from the date of payment, so interest stops on that amount.
Interest for deferment of instalments (234C): 1% × shortfall × 3 months (June, Sept, Dec instalments); 1% × shortfall × 1 month (March instalment); Shortfall is measured against 15%, 45%, 75% and 100% of tax on returned income, after TDS/TCS. No interest on the June or Sept instalment if cumulative payment is at least 12% or 36% respectively.
Interest on TDS default: Late deduction: 1% per month or part month. Late deposit after deduction: 1.5% per month or part month; Late deduction is counted from the date it was deductible to the date of deduction. Late deposit is counted from the date of deduction to the date of deposit.
TDS deposit due date: Government deductor: same day if without challan. Others: 7th of the next month. March deductions: 30 April; Check the exact timing rules for your question. Special cases (such as certain property and contract payments) have separate due dates.
Appeal time limits: To CIT(A): 30 days from service of the notice of demand or the order appealed against | To ITAT: 60 days from receipt of the CIT(A) order | To High Court: 120 days from receipt of the ITAT order; Condonation of delay is possible for sufficient cause. The High Court hears only a substantial question of law.
Reassessment time limit: Notice can be issued up to 3 years from the end of the relevant tax year; up to 5 years where the income escaping assessment is ₹50 lakh or more; For the 5-year limit, the escaped income of ₹50 lakh or more must be in the form of an asset, expenditure or entry. Check the procedural conditions and approvals in the law applicable to your attempt.
Penalty for under-reporting: 50% of tax on under-reported income; 200% of tax where income is misreported; Penalty is not automatic. Check the facts to see if it is under-reporting or misreporting.

How to solve Assessment, Procedures, TDS and Advance Tax questions

Use the same sequence for any procedure question. It keeps your answer in provision-facts-conclusion form and stops date errors.

1Identify what is being asked: TDS liability, advance tax, interest, assessment validity or appeal. Underline the dates and amounts in the case.
2Fix the governing rule in one line: for example, 'TDS applies on this payment if it crosses the threshold, at the given rate.' Use only the rate given in the question or the supplied chart.
3Check the conditions: resident or non-resident, nature of payment, threshold, PAN available, time limit. One failed condition changes the answer.
4Build a date line: due date, actual date, difference in months. Count part of a month as a full month for interest.
5Compute the base for interest carefully: tax after TDS, TCS and credits, and shortfall for each instalment. Write each line separately.
6Apply simple interest. Do not compound. Do not mix the 1% and 1.5% TDS interest rates.
7State the consequence in the same answer: disallowance, penalty, prosecution risk or appeal route, only if the facts support it.
8Conclude in one sentence with the final figure or decision, and give the reason.

Quickest way: Date line plus a two-column table

When to use it: Use it when a case study gives several payments, dates and a request to compute interest in limited time.

Draw a two-column list: 'Due' and 'Paid'. Fill in the dates and the cumulative amounts.
For 234C, compute the four targets (15%, 45%, 75%, 100% of tax on returned income) and the 12% and 36% safe limits first.
Write the shortfall for each instalment, multiply by 3% for the first three and 1% for March.
For 234B, test the 90% condition first. If advance tax is at least 90% of assessed tax, stop; no 234B interest arises.
For TDS, count months only twice: deductible date to deduction date, and deduction date to deposit date.
Add the interest heads and give one total at the end.

Common mistakes in Assessment, Procedures, TDS and Advance Tax

Computing 234B and 234C on the gross tax instead of tax after TDS and TCS
Students forget that TDS and TCS are treated as advance payments.
Fix: Always subtract TDS and TCS first. Then test the advance tax rules on the net figure.
Counting exact days instead of months for interest
Daily interest feels more precise.
Fix: Interest under 234A, 234B, 234C and TDS is by month or part of a month. A single day over counts as a full extra month.
Charging 234B interest without checking the 90% test
Students jump straight to the calculation.
Fix: Write 'advance tax paid vs 90% of assessed tax' as your first line. If the test is met, there is no 234B interest.
Mixing the TDS interest rates of 1% and 1.5%
Both rates look similar and are in the same provision area.
Fix: Remember: 1% for not deducting on time, 1.5% for not depositing after deducting. Use a separate date range for each.
Treating penalty and interest as the same thing
Both are shown as amounts payable on default.
Fix: Interest is compensation and formula-driven. Penalty depends on conduct and needs a finding such as under-reporting. Show them as separate lines.
Missing the time limit for appeal or reassessment
Students focus on merits and ignore dates in the case.
Fix: Check the date of the order or notice first. A late appeal needs condonation. A reassessment notice outside the limit is invalid.

Worked examples

Example 1

Rohan, a resident individual, has tax of ₹5,00,000 on his total income for the year, after TDS of ₹1,00,000 already deducted (the tax on returned income and the assessed tax are the same, and there are no capital gains). He paid advance tax of ₹50,000 on 14 June, ₹1,50,000 on 12 December and ₹1,50,000 on 10 March. He paid the balance as self-assessment tax and filed his return on 31 July after the year. Compute interest under 234B and 234C. The return was filed on time.

Show the solution

Tax payable after TDS = ₹5,00,000. Advance tax paid = ₹50,000 + ₹1,50,000 + ₹1,50,000 = ₹3,50,000.
234B test: 90% of ₹5,00,000 = ₹4,50,000. Advance tax paid ₹3,50,000 is less than this, so 234B applies.
234B shortfall = ₹5,00,000 − ₹3,50,000 = ₹1,50,000. The period is 1 April to 31 July = 4 months. Interest = ₹1,50,000 × 1% × 4 = ₹6,000.
234C June: target 15% = ₹75,000. Safe limit 12% = ₹60,000. Paid ₹50,000 is below ₹60,000, so interest applies. Shortfall ₹25,000 × 1% × 3 = ₹750.
234C September: target 45% = ₹2,25,000. Safe limit 36% = ₹1,80,000. Cumulative paid by 15 Sept = ₹50,000. Shortfall ₹1,75,000 × 1% × 3 = ₹5,250.
234C December: target 75% = ₹3,75,000. Cumulative paid by 15 Dec = ₹2,00,000 (₹50,000 + ₹1,50,000). Shortfall ₹1,75,000 × 1% × 3 = ₹5,250.
234C March: target 100% = ₹5,00,000. Cumulative paid by 15 March = ₹3,50,000. Shortfall ₹1,50,000 × 1% × 1 = ₹1,500.
Total 234C = ₹750 + ₹5,250 + ₹5,250 + ₹1,500 = ₹12,750. Total of both = ₹6,000 + ₹12,750 = ₹18,750.

Answer: Interest under 234B = ₹6,000. Interest under 234C = ₹12,750. Total = ₹18,750.

Example 2

Meera Ltd must deduct TDS of ₹40,000 on a payment to a resident contractor on 20 June. By mistake, it deducts the tax on 10 September and deposits it on 5 November, both within the same previous year and before the due date of filing the return. Compute the interest on the TDS default and state any other consequence on the expense.

Show the solution

Late deduction: the tax was deductible on 20 June but deducted on 10 September. The period 20 June to 10 September covers 3 months or part of a month (20 Jun–19 Jul, 20 Jul–19 Aug, 20 Aug–10 Sep).
Interest for late deduction = ₹40,000 × 1% × 3 = ₹1,200.
Deposit due date: tax deducted in September is due by 7 October. The actual deposit on 5 November is late.
Late deposit: counted from the date of deduction (10 Sept) to the date of deposit (5 Nov). The period covers 2 months or part (10 Sep–9 Oct, 10 Oct–5 Nov).
Interest for late deposit = ₹40,000 × 1.5% × 2 = ₹1,200.
Total interest = ₹1,200 + ₹1,200 = ₹2,400. This interest must be paid before filing the TDS statement.
Other consequence on the expense: none. The tax was deducted within the year and deposited before the due date of filing the return, so no disallowance arises. Only interest applies.
For comparison, the disallowance (30% of the expense for payments to residents) applies only where the tax is not deducted at all in the year, or is deducted but not deposited by the due date of filing the return. In that case the disallowed part becomes allowable in the year the tax is deducted and deposited. Check the conditions in the law applicable to you.

Answer: Total interest = ₹2,400 (₹1,200 for late deduction and ₹1,200 for late deposit). No disallowance of the expense arises on these facts, because the tax was deducted within the year and deposited before the return due date.

Exam tips

In a case study, the dates are the answer. Mark every date in the facts before you read the questions.
For MCQs on interest, test the condition (90% for 234B, 12% and 36% for 234C) before any calculation. There is no negative marking, but a wrong condition gives the wrong value.
Write the rule, the facts and the conclusion in separate lines in descriptive answers. Examiners give marks for each step.
Do not quote a section number unless it is given in the question or you are certain of it. Describe the rule in words.
In IBS, tie the tax point to the business story: a restructuring, a payment to a non-resident or a sale of an asset may carry a TDS or advance tax consequence. Mention it briefly and move on.

Practice questions from Direct Tax Laws & International Taxation

Assessment, Procedures, TDS and Advance Tax in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Assessment, Procedures, TDS and Advance Tax: frequently asked questions

How do I compute interest under 234B and 234C quickly?

Work on tax after TDS and TCS. For 234B, check that advance tax is at least 90% of assessed tax, then charge 1% per month on the shortfall from 1 April to payment. For 234C, list the four targets, find each shortfall and charge 3% on the first three and 1% on the March shortfall.

Who has to pay advance tax?

Any taxpayer whose tax payable after TDS and TCS is ₹10,000 or more in the year. Eligible presumptive taxpayers pay the whole amount in one instalment by 15 March. Check the exceptions in the law applicable for your attempt.

What is the usual order of appeal in income tax?

The first appeal goes to the Commissioner (Appeals) within 30 days of the demand notice. The second goes to the Appellate Tribunal within 60 days of the order. The third goes to the High Court within 120 days, and only on a substantial question of law.

Is interest the same as penalty?

No. Interest is compensation for delay or short payment and is calculated by formula. Penalty is imposed for conduct such as under-reporting or misreporting of income and depends on the facts. In your answer, show them as separate heads.

Do I need to remember TDS rates for the exam?

Learn the structure: the type of payment, the threshold and the person liable. Use the rate given in the question or supplied chart. Rates and thresholds change, so practise the method rather than memorising a single number.