The Goods and Services Tax (GST), introduced in India on July 1, 2017, revolutionized the indirect tax regime by subsuming multiple taxes into a unified framework. While GST simplified tax compliance in many ways, it also introduced a structured mechanism for assessment- A critical process for determining tax liability and ensuring compliance. Assessment under GST is not merely a procedural formality; it is the backbone of tax administration, ensuring that the right amount of tax is collected at the right time.
Section 2(11) of the CGST Act defines "assessment" as the determination of tax liability under the Act, and it includes self-assessment, re-assessment, provisional assessment, summary assessment, and best judgment assessment.

Self-Assessment (Section 59)
Self-assessment is the default and most common form of assessment under GST. Every registered taxpayer is required to assess their own tax liability and file returns accordingly.
Key Features
- Mandatory for all registered persons.
- Taxpayers compute their own liability and file returns under Section 39.
- Forms the basis for all other assessments.
Practical Implication
If a taxpayer files incorrect returns or underreports liability, it may trigger scrutiny or further assessments by the department.
Provisional Assessment (Section 60)
When a taxpayer is unable to determine the value of goods/services or the applicable tax rate, they may request a provisional assessment.
Procedure
- Application is made in Form GST ASMT-01.
- The proper officer may allow provisional payment via ASMT-04, subject to a bond and security.
- Final assessment must be completed within 6 months, extendable up to 4 years in exceptional cases.
Use Cases
- Complex valuation scenarios.
- Ambiguity in classification of goods/services.
Interest Implication
If the final liability exceeds the provisional amount, interest is payable from the original due date.
Scrutiny Assessment (Section 61)
This is a desk-based review of returns filed by the taxpayer. The tax officer scrutinizes the return for discrepancies.
Process
- Discrepancies are communicated via ASMT-10.
- Taxpayer must respond using ASMT-11.
- If satisfied, the officer issues ASMT-12; otherwise, further action may be initiated under audit or demand provisions.
Objective
To ensure voluntary compliance without initiating full-scale audits or investigations.
Best Judgment Assessment
This is invoked when the taxpayer fails to file returns or is unregistered but liable to pay tax.
Section 62 - Assessment of Non-Filers
- If a registered person fails to file returns even after notice, the officer may assess liability based on available data.
- Assessment order is issued in ASMT-13.
- If the return is filed within 30 days, the order is deemed withdrawn.
Section 63 - Assessment of Unregistered Persons
- Applicable when a person is liable to register but fails to do so.
- A Show Cause Notice (ASMT-14) is issued.
- Final order is passed in ASMT-15.
Summary Assessment (Section 64)
This is a protective assessment used in urgent cases to safeguard revenue interests.
Conditions
- Commissioner must believe that delay may adversely affect revenue.
- Assessment is passed without waiting for the usual process.
- Order is issued in ASMT-16.
The taxpayer can apply for withdrawal of the order using ASMT-17, and the officer must respond via ASMT-18.
Reassessment: The Missing Link
Interestingly, while the CGST Act defines "reassessment," it does not provide a separate procedure for it. However, reassessment may occur indirectly through:
- Rectification of errors under Section 161.
- Audit findings under Section 65 or 66.
- Investigation outcomes under Section 67.
Assessment Forms Summary
- ASMT-01 Application for provisional assessment
- ASMT-04 Order of provisional assessment
- ASMT-10 Notice for scrutiny
- ASMT-13 Best judgment assessment (non-filers)
- ASMT-14 SCN for unregistered persons
- ASMT-16 Summary assessment order
Challenges and Controversies
- Delayed Final Assessments: Provisional assessments often exceed the prescribed timelines.
- Interest Disputes: Taxpayers contest interest on provisional shortfalls.
- Lack of Clarity: No explicit procedure for reassessment creates interpretational issues.
- Technology Gaps: Automated scrutiny modules are still evolving, leading to manual errors.
Assessment under GST is a multi-tiered process that balances self-compliance with departmental oversight. While the law provides a robust framework, its effectiveness hinges on timely execution, clarity of rules, and technological support. As GST law matures, streamlining assessment procedures and reducing litigation will be key to its long-term success.