PAN application deadlines require timely filing when income, business, officer or transaction triggers are met to secure allotment. Permanent Account Number (PAN) allotment under Section 139A(3) mandates application to the Assessing Officer when specified income, business, institutional, officer or transaction triggers arise, and the Assessing Officer shall allot PAN forthwith. Time-bound application requirements correspond to each trigger: taxable income thresholds and certain institutional returns require application by the assessment or accounting year deadline; business turnover triggers require application by the end of the accounting year; entity financial transactions and their officers require application by the following year's filing deadline; specified bank cash and account-opening transactions require advance application shortly before the transaction. Others may apply at any time.