<h1>Assessees must comply with tax summons and notify authorities if the matter is under another inquiry under Income Tax Act</h1> An assessee is legally required to comply with summons and respond to show cause notices issued by central or state tax authorities under the Income Tax Act. The Supreme Court clarified that issuance of a summons alone does not confirm initiation of proceedings. If an assessee learns that the matter is already under inquiry by another authority, they must promptly inform the subsequent authority in writing. The tax authorities must then coordinate to avoid duplication of investigations and optimize resource use. If investigations concern different subject matters, authorities must notify the assessee accordingly. Authorities may continue inquiries until it is confirmed that both are examining the same liability, in which case duplicate show cause notices will be quashed. When overlap occurs, the authorities must decide which will proceed, with the other sharing all relevant information to conclude the inquiry. This ruling arose from a dispute involving a security services company registered under Delhi GST.