Tax Laws and Practice · Concept of Indirect Taxes at a Glance

Self-Assessment of Tax under GST (Section 59)

Updated 11 October 2026 · Fact-checked

Self-assessment under Section 59 of the CGST Act means every registered person works out the tax payable on their own and furnishes a return for each tax period under section 39. The officer does not compute your tax first. Other assessments, such as sections 60, 62 and 64, apply only in special cases.

Understand Self-Assessment of Tax under GST (Section 59)

Under older indirect tax laws, the officer often decided how much tax you owed. GST changed this. The law trusts the taxpayer to work out the tax and report it.

Section 59 says: every registered person shall self-assess the taxes payable under the Act and furnish a return for each tax period as specified under section 39. So you decide the value of supply, the rate, the tax due and the credit you claim. You then declare it in your return.

Self-assessment is the default form of assessment under GST. It applies to every registered person, whether or not any officer is looking at the case. The return is the vehicle through which you report your own assessment. Because you assess yourself, you also carry the responsibility if the assessment is wrong.

The other assessments are exceptions. They apply when something goes wrong or when you need special permission. They are provisional assessment (section 60), assessment of non-filers of returns (section 62) and summary assessment in special cases (section 64). Scrutiny and tax demand under other sections follow the same logic: the department steps in only after your own assessment.

The same idea exists in customs. Under section 17 of the Customs Act, 1962, the importer or exporter self-assesses the duty on the bill of entry or shipping bill. The officer may later verify and re-assess. This is why the chapter treats both together.

Key rules to remember

Section 59 rule: Registered person → self-assesses tax payable + furnishes return for each tax period (section 39); Applies to every registered person. This is the default mode of assessment under the CGST Act.
Provisional assessment (section 60): Request in writing → order within 90 days → final order within 6 months of the order; Used when you cannot determine the value or the rate of tax. Needs a bond with surety or security. Extension: Joint/Additional Commissioner up to a further 6 months; Commissioner up to a further 4 years.
Non-filers (section 62): Best judgment assessment order within 5 years from the due date of the annual return for the relevant financial year; Applies after notice under section 46. If you file a valid return within 60 days of service of the order, the order is deemed withdrawn; interest and late fee continue. A further 60 days is allowed with an additional late fee of ₹100 per day.
Summary assessment (section 64): Evidence of liability + belief that delay harms revenue + prior permission of Additional/Joint Commissioner; The taxable person may apply within 30 days of receipt of the order for withdrawal.
Customs self-assessment (section 17): Importer/exporter self-assesses duty → officer may verify → may re-assess → speaking order within 15 days if contrary to self-assessment; No speaking order is needed if the importer or exporter accepts the re-assessment in writing. Verification cases are chosen mainly on risk evaluation.

How to solve Self-Assessment of Tax under GST (Section 59) questions

Use this method for any question on assessment under GST, whether it is a theory question or a short case.

1Identify the kind of assessment the facts point to: self-assessment, provisional, non-filer, or summary.
2If the person is a registered person who files returns normally, state that section 59 applies and that the person self-assesses and files the section 39 return.
3If the person cannot determine value or rate, move to section 60. Mention the written request, the bond, and the time limits.
4If the person has not filed returns even after a section 46 notice, move to section 62. Mention best judgment and the 5-year limit.
5If the facts show urgency or risk to revenue, move to section 64. Mention prior permission and the 30-day application.
6Apply the time limits and consequences to the facts given, such as filing within 60 days.
7Write a clear conclusion in one line, naming the section.

Quickest way: Trigger-word method

When to use it: Use it when the question is a short case and you must choose the right section in under a minute.

Read the facts for a trigger word.
'Registered person files return' means section 59.
'Cannot determine value or rate' means section 60.
'Not filed return despite notice' means section 62.
'Delay may hurt revenue' means section 64.
Write the section, the rule, and the conclusion.

Common mistakes in Self-Assessment of Tax under GST (Section 59)

Saying the officer assesses the tax first under GST.
Students carry over the idea from older tax laws or from income tax.
Fix: Remember that section 59 puts the duty on the registered person. The officer acts only afterwards or in special cases.
Applying section 59 to unregistered persons.
The word 'every' makes students read it too widely.
Fix: The text says 'every registered person'. Use that exact phrase.
Mixing up the time limits of sections 60, 62 and 64.
Several numbers look alike: 90 days, 60 days, 30 days, 6 months.
Fix: Tie each number to its section: 90 days for the provisional order (60), 60 days for filing after a non-filer order (62), 30 days for the application against a summary order (64).
Forgetting that interest and late fee continue after a section 62 order is withdrawn.
Students think withdrawal wipes out all liability.
Fix: Add the line: the order is deemed withdrawn, but interest under section 50(1) and late fee under section 47 continue.
Treating provisional assessment as a free choice.
Students forget the conditions.
Fix: State that it needs a written request with reasons and a bond with surety or security, and that the final order follows within six months, extendable.
Confusing GST self-assessment with customs self-assessment.
Both use the same word but sit in different Acts.
Fix: Cite section 59 CGST for GST returns and section 17 Customs Act for bills of entry and shipping bills.

Worked examples

Example 1

Explain the meaning of self-assessment under the CGST Act, 2017. Who must do it, and how is it reported?

Show the solution

Provision: Section 59 requires every registered person to self-assess the taxes payable under the Act.
Analysis: The person determines the value, rate, tax payable and credit. This is reported by furnishing a return for each tax period as specified under section 39.
Contrast: The officer does not compute tax at the first stage. Assessments under sections 60, 62 and 64 apply only in special situations.

Answer: Under section 59, every registered person must assess their own tax and furnish a return for each tax period under section 39. Self-assessment is the default mode of assessment under GST.

Example 2

Shree Traders Pvt. Ltd., a registered person, did not file its return for a tax period even after a notice under section 46. On 10 March the proper officer served an assessment order under section 62. The company filed a valid return on 25 April, which is within 60 days of service. What is the effect?

Show the solution

Provision: Section 62(1) allows the proper officer to assess to the best of his judgment where a registered person fails to file the return even after notice under section 46.
Section 62(2): If a valid return is filed within sixty days of service of the order, the order is deemed withdrawn.
Facts: From 10 March to 25 April is 21 days left in March plus 25 days in April, which is 46 days. This is within 60 days.
Consequence: Interest under section 50(1) and late fee under section 47 continue to be payable.

Answer: The assessment order is deemed withdrawn because a valid return was filed within 60 days. The company must still pay interest under section 50(1) and late fee under section 47.

Exam tips

Quote section 59 in the first line of your answer. ICSI answers reward the provision first, then analysis, then conclusion.
Write the contrast between self-assessment and the special assessments in a short list. Examiners often ask for the difference.
Learn the numbers for sections 60, 62 and 64 as a small table in your notes and revise them just before the exam.
For customs, mention section 17 only when the question is about duty on imports or exports.
End case answers with a one-line conclusion that names the section.

Practice questions from Concept of Indirect Taxes at a Glance

Self-Assessment of Tax under GST (Section 59) in other exams

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

Self-Assessment of Tax under GST (Section 59): frequently asked questions

What does section 59 of the CGST Act say?

It says every registered person shall self-assess the taxes payable under the Act and furnish a return for each tax period as specified under section 39. The person works out the tax and reports it in the return.

What is the difference between self-assessment and scrutiny assessment under GST?

In self-assessment, the registered person computes the tax and files the return. In other assessments, the officer steps in, for example to assess a non-filer to the best of judgment under section 62 or to make a summary assessment under section 64. Provisional assessment under section 60 is allowed only on request and on a bond.

Can a person pay tax on a provisional basis under GST?

Yes, if the person cannot determine the value of supply or the rate of tax. They must request the proper officer in writing with reasons and execute a bond. The officer passes an order within 90 days of the request.

Is there self-assessment under the Customs Act too?

Yes. Under section 17 of the Customs Act, 1962, the importer or exporter self-assesses the duty on the goods. The proper officer can verify the entries and re-assess if the self-assessment is wrong.