This document discusses interest payable by and to taxpayers in various situations under the Indian Income Tax Act. It covers interest charged for late filing of returns, late payment or underpayment of advance tax, excess refunds granted, and interest paid on amounts seized during a search that are eventually refunded. The key points covered include calculation methods for different types of interest, applicable rates, and time periods over which interest applies. Case laws are also referenced related to issues like what date should be used to determine interest and whether interest can be charged without being specified in the assessment order.