Supplementary drawback claim: time limits and extension rules govern filing, fees, and resubmission consequences under customs rules. An exporter may prefer a supplementary claim where drawback paid is less than entitlement; such claim must be made within three months from specified triggers, subject to discretionary extensions (Assistant/Deputy Commissioner: +9 months; Principal/Commissioner: further +6 months) on application and payment of prescribed application fees. The filing date is the date of affixing the Dated Receipt Stamp and issuance of acknowledgement. Incomplete claims returned within fifteen days with a deficiency memo are deemed not filed; resubmitted compliant claims are treated as filed for statutory purposes.