Remnant ATF duty payment via provisional prior bill with advance deposit enables debit-based clearance after post-landing quantity verification. Procedure prescribes filing a Prior Bill of Entry with an estimated remnant ATF quantity, provisional assessment backed by a Provisional Duty Bond and an Advance Duty Deposit from which provisional duty is debited; actual quantity is determined after landing from the aircraft log/pilot declaration, leading to final assessment within seven days after endorsing the IGM, audit and manifest closure linking duty payment to the IGM, with an alternate regular Bill of Entry option for non-participating airlines.