Rule 166: Defective-return conditions and pre-filing checks
Rule 166 lists four conditions that can make a return defective under section 263(7). It focuses on completed applicable fields, the required pre-return audit report, updated-return payment details and consistency of an allowed MAT or AMT credit claim.
Official notified Income-tax Rules, 2026Need advice on Rule 166?
This article is for general information. Read the official Rules and applicable Act amendments, including the Taxation and Other Laws (Amendment) Act, 2026. If you need professional advice for your situation, contact Bizeneed.
On this page
- Bare law
- Complete every applicable field and schedule
- File the specified audit report before the return
- Updated returns must include the required payment details
- Credit consistency does not create a new credit entitlement
- Review notifications and the parent correction procedure
- Key takeaways
- Practical checklist
- FAQs
- Glossary
- Official sources
Bare law
Rule 166 - Conditions for treating a return as defective return under section 263(7)
(1) A return of income shall be regarded as defective, if any of the following conditions is satisfied: — (a) all fields, parts, schedules, statements, and columns in the return of income, as applicable to the case of the assessee, have not been duly filled in, including those relating to computation of income chargeable under applicable heads of income, computation of gross total income and total income; or (b) the report of the audit, in auditable cases, referred to in section 63, has not been furnished prior to the filing of the return of income; or (c) if the return of income is furnished under section 263(6), the details of payment of tax as per section 267 are not duly filled in the return; or (d) the brought forward credit of minimum alternate tax (MAT) or alternate minimum tax (AMT) claimed in the return is not in accordance with the carry forward of MAT or AMT in the latest return, as the case may be, allowed to the assesse.
(2) The Board may notify, the class or classes of persons, to which any of the conditions specified in clauses (a) to (d) of sub-rule (1), shall not apply or shall apply with such modifications, as may be specified in such notification.
Rule breakdown
Complete every applicable field and schedule
The first condition concerns applicable fields, parts, schedules, statements and columns not being duly completed, including income-head, gross-total-income and total-income computations.
Use the taxpayer’s facts to identify applicable schedules. Do not assume acceptance by a filing screen proves every statutory information requirement is satisfied.
File the specified audit report before the return
For the auditable cases described, failure to furnish the section 63 audit report before filing the return is a defect condition.
Keep the report acknowledgment and filing sequence. An annexure-free return does not remove this separate pre-return report requirement.
Updated returns must include the required payment details
For a section 263(6) updated return, the section 267 payment details must be duly filled in.
Reconcile the computation and actual payments to the details entered in the updated return rather than retaining payment evidence outside an incomplete form.
Credit consistency does not create a new credit entitlement
The MAT or AMT credit claimed must accord with the carry-forward in the latest return as allowed to the assessee. Check current section 206 and the relevant legacy-credit restrictions before assuming a credit is substantively available.
The defect rule checks a claim’s consistency; it does not reinstate an omitted entitlement or allow every historical credit merely because it appeared in a prior return.
Review notifications and the parent correction procedure
The Board may notify classes to which the listed conditions do not apply or apply with modifications. Check any applicable notification.
If a defect notice is received, read section 263(7) and the actual notice for the rectification procedure and period. This rule lists conditions; it does not itself reproduce the complete remedy or notice process.
Key takeaways
Four defect categories
Complete schedules, audit filing, updated-return payments and credit consistency matter.
Audit comes first where required
Retain the filing chronology.
Credit must also be lawful
Consistency alone does not create entitlement.
Notifications may modify conditions
Check the applicable taxpayer class.
Practical checklist
- Complete every applicable schedule.
- Confirm the audit-before-return sequence.
- Reconcile updated-return payments and permitted credits.
- Respond to the actual notice within the applicable process.
Avoid
- Do not treat prior-return figures as automatic current credit entitlement.
- Do not assume portal acceptance proves statutory completeness.
FAQs
Can an annexure-free return still be defective for missing audit filing?
Yes. Rule 166 specifically addresses failure to furnish the required audit report before the return.
Are payment details optional in an updated return if tax was paid?
The rule requires the section 267 payment details to be duly filled in the updated return.
Does this rule revive all prior MAT credits?
No. It addresses consistency of an allowed claim; current section 206 and applicable credit restrictions remain relevant.
Does this rule give the whole defect-correction procedure?
No. Read current section 263(7), relevant notifications and the actual notice.
Glossary
- Defective return
- A return falling within the stated section 263(7) framework and the conditions prescribed here.