Section 59 explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
The shortest section in Chapter XII carries more weight than the rest of it combined.
Section 59: "Every registered person shall self-assess the taxes payable under this Act and furnish a return for each tax period as specified under section 39." Everything else in the Act — scrutiny, audit, demands, best judgment assessment — is a mechanism for verifying or displacing that self-assessment. The department does not assess in the first instance; it responds to what the taxpayer has assessed.
What follows from it
No assessment order in the ordinary course. A compliant taxpayer never receives one. The return is the assessment.
The return is a determination. Which is why s.75(12) allows recovery of self-assessed tax without a show cause notice: "Notwithstanding anything contained in section 73 or section 74, where any amount of self-assessed tax in accordance with a return furnished under section 39 remains unpaid, either wholly or partly, or any amount of interest payable on such tax remains unpaid, the same shall be recovered under the provisions of section 79."
The Explanation to s.75(12), inserted from 01.01.2022, clarifies that "self-assessed tax" includes the tax payable in respect of details of outward supplies furnished under s.37 but not included in the return furnished under s.39.
So a liability declared in GSTR-1 but not paid in GSTR-3B is self-assessed tax recoverable without adjudication. That is the statutory basis for Rule 88C and DRC-01B. Rule 88C and DRC-01B →
The verification layers
Section 61 — scrutiny. A desk comparison of the return against related particulars, with discrepancies communicated in ASMT-10. Not an assessment. Section 61 scrutiny →
Section 65 — audit by tax authorities. A structured examination of records for a period, at the officer's premises or the taxpayer's, with ADT-01 notice and ADT-02 findings.
Section 66 — special audit. By a chartered accountant or cost accountant nominated by the Commissioner, where the case is complex and the interest of revenue requires it, at the Commissioner's expense.
Section 67 — inspection, search and seizure. Where there is reason to believe suppression.
Each of these verifies. None of them determines a liability. Determination happens under s.73, s.74 or s.74A.
The displacement layers
Section 60 — provisional assessment. Where the taxable person is unable to determine the value or the rate, he may request provisional assessment; the officer passes an order within ninety days, on a bond with security, and finalises within six months, extendable.
Section 62 — assessment of non-filers. Best judgment, where the return was not filed after a s.46 notice. Withdrawn if the return is filed within sixty days. Sections 46 and 62 →
Section 63 — assessment of unregistered persons. Best judgment, within five years of the annual return due date, after an ASMT-14 notice.
Section 64 — summary assessment. In special cases, with the Additional or Joint Commissioner's prior permission, where the officer has evidence of a liability and sufficient grounds to believe that delay will adversely affect the interest of revenue.
These replace the self-assessment for the period, rather than verifying it.
Why the distinction matters in practice
A scrutiny notice is not a demand. ASMT-10 seeks an explanation. It cannot be appealed, and nothing is payable under it. Section 61 scrutiny →
An audit finding is not a demand. ADT-02 communicates findings. A demand requires a separate s.73, s.74 or s.74A notice.
Self-assessed tax needs no notice to recover. Section 75(12) is the exception, and it covers exactly the GSTR-1 versus GSTR-3B gap.
A best judgment order is an assessment. It replaces the return, is appealable, and can be withdrawn only through the specific mechanism in s.62(2).
Answering the wrong instrument — treating an ASMT-10 as a demand, or a DRC-01B as a scrutiny notice — wastes the response and can concede the point.
The consequence for a taxpayer
Because the system is self-assessment, the quality of the return is the quality of the tax position. There is no departmental assessment that will catch an error benignly; there is only verification that finds it years later with interest.
That is why the reconciliations matter, and why they must happen before filing rather than after. The eight reconciliations →
Key takeaways
- Section 59: every registered person self-assesses and furnishes a return.
- s.75(12): self-assessed tax unpaid is recoverable under s.79 without a notice.
- The Explanation extends "self-assessed tax" to liability in GSTR-1 not paid in GSTR-3B.
- Sections 61, 65, 66 and 67 verify; they do not determine.
- Sections 60, 62, 63 and 64 displace the self-assessment in defined situations.
- Determination of a liability happens only under s.73, s.74 or s.74A.
Read next
- Assessment Under GST: Self, Provisional and Best Judgment
- Section 61 Scrutiny: ASMT-10 and the Thirty-Day Reply
- Sections 46 and 62: What Happens When You Do Not File
- The Eight Reconciliations That Prevent GST Notices
Disclaimer: Positions stated as on 5 September 2026, based on the CGST Act as amended to 31 March 2026 (ICAI Bare Law, 12th edition).