Advance tax default: three independent triggers establish deemed default and activate statutory consequences for noncompliance.
Clause 409 deems a taxpayer in default for advance tax where the taxpayer fails to: pay an instalment specified by an Assessing Officer by the due date; send an intimation of revised liability to the Assessing Officer by the date an unpaid instalment becomes due; or pay advance tax based on the taxpayer's own estimate of current income. The clause frames these three independent triggers as grounds for deeming default, thereby activating statutory consequences such as interest, penalties, and recovery measures.