Obligation to quote PAN: expedite allotment, certify allotment for live cases, and cease use of GIR numbers. The instruction directs expeditious allotment and communication of Permanent Account Number (PAN), emphasises the statutory obligation to quote PAN on returns, challans and correspondence, requires commissioners to certify that PANs have been allotted in all live cases on the Department's register as of the reference date, and reiterates that use of GIR numbers must be discontinued in favour of PAN for registers and correspondence.