Unique Client Code requirement makes PAN the mandatory identifier for commodity derivatives trading, with penalties for noncompliance. Mandatory implementation of a Unique Client Code (UCC) requires members of commodity derivatives exchanges to collect, verify and upload clients' Permanent Account Number (PAN) as the sole identification for trading, subject to specified exemptions. Members must verify PAN with originals and the Income Tax Department database, retain copies, update client particulars monthly within seven working days of the following month, and exchanges must maintain a seven year historical database. Noncompliance attracts a trade penalty transferred to the Investor Protection Fund and potential member suspension for delayed uploads.