Challan correction for PMGKY payments to regularize Form 1 filings when procedural errors prevented timely recognition. The circular permits administrative correction of PMGKY challans where tax and required deposits were paid on time but recorded with incorrect challan particulars, while excluding PMGKD deposit corrections as outside CBDT authority; it prescribes allowable correction types (assessment year, PAN, specified major and minor head changes), requires jurisdictional recommendations assessing bona fides, directs Systems to process corrections and notify declarants, and sets deadlines for subsequent filing of Form 1 and issuance of Form 2 following verification.