Image: MSC IRINA TRIVANDRUM PORT HD by Giridharseeman, licensed under CC0 1.0.
You cleared a demurrage invoice in March. In April the carrier published a notice that moved the start of free time on those same containers back by three weeks, and the amount you approved is now wrong by several days on every box.
That is not a hypothetical. Maersk's advisory of 1 April 2026 on the Strait of Hormuz disruption tells customers that for containers discharged in India between 3 and 25 March 2026, where the cargo went to an Indian port of refuge and the final destination then changed to India, combined demurrage and detention free time begins on 26 March 2026 rather than on the actual discharge date. Terminal storage keeps accruing through the period. The free time clock does not.
Every audit that touched one of those containers was right when it was made and wrong a week later. What your system does next is the whole question, and the usual answer is the one thing you cannot defend afterwards.
Arriving late is the normal case
Changes to free time are sometimes announced in advance. Maersk raised the demurrage free period at Durban Gateway Terminal from three to five calendar days for general purpose dry and non-operating reefer boxes, effective 1 October 2026, as Container News reported on 4 October. Nothing already invoiced moves, so nothing already audited has to be revisited.
Everything else lands after the fact. A terminal corrects a gate record. An arrival notice is amended. A credit note turns up against an invoice you argued about six weeks ago. An entry behind the shipment gets a post summary correction, which CBP describes as the sole method for the trade to electronically correct an entry summary before liquidation, filed within 300 days of the entry date or up to 15 days before scheduled liquidation, whichever comes first. Roughly nine months of permitted change sits behind a charge your team settled in four days.
The underlying record stays open longer still. 19 CFR 163.4 requires records relating to an entry to be kept for five years from the date of entry. Under 19 USC 1504 an entry not liquidated within one year is deemed liquidated at the rate, value, quantity and duty the importer declared, and 19 USC 1514 then allows a protest within 180 days after that liquidation. The obligation behind a container has a life measured in years. Most freight audit tools treat their own conclusion as final the moment the payment file goes out.
Overwriting destroys the proof that you were right
When the late document lands, the common behaviour is an update in place. The free time start date changes, the chargeable day count recomputes, a variance appears, somebody reconciles it. The file now reads as though the corrected dates were known all along.
Three things break at once, and the first is your own defence. 46 CFR 541.7(a) requires a billing party to issue a demurrage or detention invoice within 30 calendar days of the date the charge was last incurred, and relieves the billed party of payment if it does not. Subsection (d) applies the same 30 day limit to a corrected invoice issued to the right party after the wrong one was billed. Both tests run against the issuance date of the document you originally received. Replace that field and the argument disappears, because you can no longer evidence when anything actually arrived.
The second is the dispute clock. 46 CFR 541.8 requires the billing party to allow at least 30 calendar days from the invoice issuance date for a request for fee mitigation, refund or waiver, and to attempt to resolve that request within 30 calendar days of receiving it, unless both sides agree a later date. A revised charge carries its own window. If the revision silently replaces what came before, nobody on your side can say which window is currently running or whether the earlier one closed unanswered.
The third is double counting. Say you disputed nine days on a box, the carrier waived four, and finance booked the recovery. Five weeks later the carrier reissues the invoice with the waiver already applied. A system that updates in place sees a smaller amount against the same container, computes a fresh variance, and books the same four days a second time. Nothing in the record connects the two events, because the record only ever holds one.
| Question | Under overwrite | Under supersession |
|---|---|---|
| What did you know on the day you approved? | Unanswerable, since the file shows today's data | Version one is intact with its own received dates |
| Was the invoice issued inside the 30 day window? | Lost as soon as the date field is replaced | Original issuance date preserved on version one |
| How much is still recoverable? | The full restated gap, part of which may be claimed already | The difference between version one and version two |
| Which dispute window applies? | One charge with one ambiguous clock | Each version carries its own request and resolution dates |
Two clocks, not one
The modelling answer is older than the problem. SQL:2011, published as ISO/IEC 9075:2011, gave the standard two independent time dimensions. An application-time period records when a fact holds true in the world. A system-versioned table carries a SYSTEM_TIME period recording when the database learned it, maintained automatically and queryable with AS OF SYSTEM TIME. A table may define at most one of each, and the two move apart from one another freely.
Hold the Maersk notice against that. The free time change is true from 26 March 2026. It became knowable on 1 April 2026. A ledger with a single date column cannot carry both, so it keeps whichever was written last and thereby asserts that your team knew in March what the carrier published in April.
Accounting draws the same boundary. FASB's ASC 250 separates a correction of an error, which requires previously issued statements to be adjusted, from a change in estimate, which is recognised in the period of the change and going forward. A document that did not exist on audit day is not a mistake in the audit. It is later information about the same event, and it earns different treatment.
How Penny handles a document that shows up late
Penny records audit positions as versions and never as edits. Version one holds the invoice as received, the supporting documents available at the time, the day count, the cause attribution, the decision and the timestamps for all of it. That version is closed the moment it is written.
A late document opens version two. It cites the document that triggered it, stamped with the date Penny received it rather than the date it claims to be effective from, and the day count is rebuilt rather than patched. The ledger then posts only the difference between the two versions, which is what keeps a reissued invoice from being harvested twice. Our post on duplicate invoices covers the adjacent failure, where the same charge arrives twice wearing different reference numbers.
Version two does not disturb the timeliness tests. Penny still runs 541.7 against the issuance date on version one, because that is the date that decides whether the original charge was payable at all. If the recomputation changes nothing owed, version two is still written, so the file shows that the notice was seen and assessed.
Chase supplies the event trail each version is rebuilt from: discharge, availability, release, gate out, empty return. Supersession without an independent event record is just a tidier way of accepting whatever the carrier sent most recently.
Where to start
Pick the last twenty ocean charges that were revised after you paid them and check three things.
- Can you produce the original invoice with its original issuance date, or only the current version?
- For each revision, does the file record the date you received it separately from the date it takes effect?
- Where a revision reduced a charge you had already disputed, did finance book one recovery or two?
If the first answer is the current version only, the other two are unanswerable. That is not an audit trail. It is a running total that forgets its own working.
Book a walkthrough to see Penny version an ocean charge against a document that arrives three weeks after the decision.