A retention table for 19 CFR part 163 needs more than one start date, and a schema that stores only an entry date will misclassify every packing list in the system.

The problem is that the regulation states several different clocks. Under 19 CFR 163.4(a), a record required to be made, kept, and rendered for examination and inspection by Customs is kept for 5 years from the date of entry if the record relates to an entry, or 5 years from the date of the activity which required creation of the record. Those are two distinct start events, and the second one is not a fallback for the first. Paragraph (b) then carves out exceptions with their own anchors. Records behind a drawback claim survive until the third anniversary of payment. Packing lists run 60 calendar days past the close of the release or conditional release period, or past whichever of those dates lands later, and a second 60-day clock attaches to redelivery where Customs has demanded the goods back.…