Your COGS is a number you typed in once.

Almost every seller enters the supplier invoice as their cost. Duty arrives weeks later on a different document, from a different party, and is filed against the shipment rather than the SKU. It never finds its way back to the unit.

Boltless steel shelving from China enters under 9403.20.0075 at a Column 1 General rate of Free — and is then charged 50%: a Section 232 derivative heading in Chapter 99 adds 25% on the full customs value (where steel is at least 15% of the weight), and Section 301 List 3 adds another 25%. Nothing in your Amazon account or your spreadsheet knows either heading exists. A line that reads Free and is really 50% is the exact failure this product exists to catch.

The USITC publishes the tariff as a machine-readable export with a column named Additional Duties. It is empty — on 955 of 955 consumer-goods rows and 125 of 125 primary steel rows. Stainless steel kitchenware from China prints 2% there; the real figure is 27%, once the 25% Section 232 derivative charge on the full value is added. It is wrong the other way too: 73 Chapter 99 headings still print live rates of 10–41% after being abolished on 20 February 2026, with no termination note. Same file, same line, wrong in both directions.

Amazon shipped its own per-SKU profit dashboard in September 2025. It still asks you to type in your cost, and it always will — Amazon does not know what you wired your supplier, what your forwarder charged for the leg into Long Beach, or what CBP assessed when your entry summary was filed. That is not a gap Amazon is choosing to leave. It is a permanent asymmetry.

Every tool downstream of Amazon inherits the same blind spot. They compute beautiful margins on a number you guessed.

• 20 Feb 2026IEEPA China tariffs terminated outright by EO 14389 — and the HTS still prints the dead headings.
• 24 Feb 2026A Section 122 balance-of-payments surcharge imposed at 10%.
• 6 Apr 2026Section 232 moved to the full customs value, regardless of metal content, by Proclamation 11021.
• 23 Jul 2026The Section 122 surcharge expired at the close of the day.
• 24 Jul 2026A Section 301 forced-labour action took effect.
• 14 Sep 2026Section 338 duties applied to Canada by proclamation.

Commerce adds derivative categories to the Section 232 lists through an inclusions process that runs in fixed submission windows — the August 2026 notice closed comments on the 27th. A product line outside the scope in one window can be inside it after the next, decided on a docket nobody outside the trade bar reads. The dates exist; they are just not yours.

That is the honest reason this is a subscription. A one-off audit tells you what your landed cost was on the day it was run, which is worth having and is where we start. Keeping it true is a different job, and it does not finish.

Classification is a judgement. It is why binding rulings exist and why you pay a broker. A tool that reads your product title and proposes a heading is offering you a liability dressed as a feature, and the first time it disagrees with your broker you will — rightly — stop trusting all of it.

In the United States it is also the law. Customs business is licensed under 19 U.S.C. 1641, and CBP has held that checking tariff numbers ahead of entry falls inside it wherever the corrected number could reach the entry — including against a software vendor whose customers all used licensed brokers, and including where the output was labelled advisory. Reviewing entries already filed, to tell an importer how accurate they were, is expressly outside it. That is the side of the line this product was built on, and it is not a line we intend to test.

So Supercargo takes the code from your own entry, declared by your own broker, in your own name, to a government. Where there is no entry, the SKU is marked unclassified and shows up in the gaps ledger. It never quietly guesses.

Sellerboard shows you the profit on the cost you typed in. Supercargo computes the cost: FOB plus freight plus duty plus any Chapter 99 charge or anti-dumping measure, per unit, then checks it against the duty actually assessed on your entry summary. If your typed-in COGS is right, the two agree and you have learned something. Usually they do not agree.

Your broker files the entry correctly against the code you gave them. They do not tell you what that duty did to the margin on SKU 14, and they do not revisit a classification you have been carrying for three years. Supercargo does not file anything, does not replace your broker, and does not tell you what to declare — it reads what was filed and joins it to what you sold.

No. Never. Supercargo is management accounting software. It reads documents you supply and published tariff data. It is not a customs broker, it does not conduct customs business as defined in 19 CFR 111.1, and it makes no declarations. Your licensed broker remains the decision-maker, and where anything we show differs from your broker, your broker governs.

Your entry summaries — CBP Form 7501 — and the commercial invoices behind them. If you are the importer of record you can self-enrol in ACE yourself in about ten minutes, and schedule the Entry Summary Line Tariff Details report as a recurring CSV emailed to any address you choose, covering the five years CBP requires you to keep anyway. No API, no power of attorney, no filer code, no broker licence, and nothing for you to share a password to. Scanned PDFs work too, but they are the fallback rather than the plan. If you also import into the UK, the equivalent CSV comes from HMRC’s customs data report service.

It might, and it is worth checking before anything else. If a broker has associated your importer number to their own ACE top-level account, you cannot create your own — and the verification code goes to the point-of-contact email on your CBP Form 5106, which is often the broker’s inbox rather than yours. That is the default state after a long broker relationship, it is fixable, and it is the first thing we look at. ACE has no third-party authorisation of the kind the UK has: a Service Provider sub-account cannot run reports at all, so there is no version of this where you hand us a credential.

No, and that refusal is structural rather than modest. Classification is customs business, it is licensed under 19 U.S.C. 1641, and CBP has held that checking tariff numbers before entry counts even where a licensed broker files every entry and even where the output is labelled advisory. Supercargo works backwards from the code you already declared, on entries already filed. Where there is no entry, the SKU is marked unclassified and appears in the gaps ledger.

By design, landed cost, duty, the purchase-order ledger, containers and cash flow never touch Amazon — they run on your own documents, and the architecture keeps them in a separate schema so they survive losing the Amazon connection. The Amazon-derived screens stop; those do not. And the audit never touches Amazon at all — it runs entirely on your CBP entry summaries and the invoices behind them.

No, and we think that would make your security worse rather than better. The only version of self-hosting Amazon’s rules permit makes you the permanent custodian of a client secret with no rotation tooling and no revocation screen. Instead you get your own isolated database, your own encryption key, and an Amazon authorisation you can revoke yourself in two clicks.