Section 523
Section 523: notice deemed to be valid in certain circumstances
Section 523 stops an assessee from raising a service-of-notice objection late in the day: if the assessee has appeared in a proceeding or cooperated in an inquiry relating to an assessment or reassessment, the law treats any notice required to be served as having been duly served in time - unless the assessee raised the objection before the assessment or reassessment was completed.
When a notice is deemed validly served
Where an assessee has appeared in any proceeding or co-operated in any inquiry relating to an assessment or reassessment, it shall be deemed that any notice under the Act which is required to be served upon him has been duly served upon him in time as per the provisions of this Act. As a result, the assessee is precluded from taking any objection in any proceeding or inquiry under the Act that the notice was:
- Not served upon him
- Not served upon him in time
- Served upon him in an improper manner
The exception
The deeming rule in sub-section (1) does not apply where the assessee has raised such an objection before the completion of the assessment or reassessment. So it only protects the department where the assessee stayed silent about the service defect until after the assessment/reassessment was completed - if the objection was raised earlier, it survives.
Frequently asked questions
Can an assessee always object to how a notice was served?
Not always - under Section 523, if the assessee appeared in the proceeding or cooperated in the inquiry, the notice is deemed validly served, and the assessee can't raise a service objection after the assessment or reassessment is completed.
How can an assessee preserve the right to object to service of a notice?
By raising the objection before the assessment or reassessment is completed - Section 523(2) says the deeming rule in sub-section (1) does not apply in that case.
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Talk to our tax team about this sectionLast updated 9 September 2026