Advance filing of Bill of Entry enables pre-arrival customs processing and assessment, expediting clearance timelines. Advance filing of the Bill of Entry permits pre-arrival submission and processing, valid if the conveyance arrives within thirty days; where transshipment occurs, initial entries may record the mother vessel and be amended to add feeder vessels. Amended rules require filing by the end of the day preceding arrival while preserving a thirty-day prior presentation window, and mandate mode-specific time-limits in electronic declaration regulations; late presentation attracts daily charges.