Carrier FX Surcharge: How to Check the Exchange Rate Used
The cost of a currency conversion often sits inside the rate itself, on no line of its own, so the check is to work the rate back out of the invoice.
Explainer · 6 min · Alexandre de Perregaux, CEO, Intellyse · Published · Last updated
By Intellyse, makers of freight invoice audit software · About us
Freight teams usually check a carrier invoice in the currency it arrives in: the rate card says USD 54, the invoice shows a figure in another currency, and the line is approved if nothing else looks wrong. That works when the rate card and the invoice share a currency. When they do not, the cost of the conversion can sit inside the rate, so a check for a carrier FX surcharge has to look past the surcharge lines.
What is a carrier FX surcharge?
In the broad sense the term is searched for, it is any currency-related cost on a freight invoice when a charge agreed in one currency is billed in another. It arrives through one of two different mechanisms: a separate charge, such as a currency adjustment factor (CAF), often expressed as a percentage of freight, or the exchange rate (ROE) used to convert the agreed charge. The audit needs to check which of the two the contract allows.
The first is visible and can be checked against the carrier's published table and the contract. The second is not. The invoice may print the rate it used or only the converted amount; either way, the markup is the difference between that rate and a neutral one for the same date.
How do carriers set the exchange rate on a freight invoice?
Every conversion rests on three choices: where the rate comes from, which date fixes it, and whether anything is added. The contract decides them where it names them; otherwise the carrier's own rule applies.
Maersk's notice of 23 February 2026 shows how specific that rule can be. For air and LCL invoices in the countries it lists, the ROE is sourced from LSEG and fixed on the date the first invoice for the service is created, and the same rate applies to every later or reissued invoice for that service. So, for these invoices, a rate taken from the sailing date would be the wrong comparison point.
For an external benchmark, the European Central Bank publishes euro reference rates around 16:00 CET each working day, and states they are for information purposes only. They can serve as a benchmark for an audit, not as a rate the carrier must use unless the contract says so. Because they are quoted against the euro, a pair such as USD to AUD has to be derived from two of them, the same way each time.
The gap is easy to miss because it is small per line. On one shipper's invoices on our platform, a destination documentation fee agreed at USD 54 was billed in Australian dollars at between 2.5 and 4 per cent above the agreed amount converted at the exchange rate the shipper itself provides for its audit; on the most recent invoice, AUD 78.16 against AUD 75.70.
The fee itself never changed. The exchange rate did the work.
Why does an FX markup go unnoticed?
Because the people checking the rate card and the people processing the invoice may be looking at different currencies. The rate card is in the currency of the contract, the invoice is in the currency of the billing entity, and the approver often compares the invoice with a booking rather than with the rate card. If accounts payable then converts the invoice into the company's reporting currency, a third exchange rate can enter the process.
The amounts also look plausible. A 3 per cent markup on a USD 54 fee is under USD 2. It is easy to miss on an individual line and becomes visible when it is summed across shipments, or when the same fixed fee is traced across months and found to move with the exchange rate rather than stay where it was agreed.
How do you check the exchange rate a carrier used?
A consistent gap is grounds for a query, not proof of an overcharge: the contract and any tariff incorporated into it decide which rate was payable. Our Cost to Serve module shows what each lane, carrier and cost category actually costs, built from the audited invoice lines, so a currency effect on fixed fees can be tracked over time instead of found once by accident. To see what the exchange rates on your own invoices add, we offer a free analysis on 100 shipments.
Free freight audit, 100 shipments
We audit 100 of your shipments and show you the savings.
- You send 100 recent invoices with the matching shipment data and rate agreements, as file exports.
- We check every line against the contracted rates and the shipment data and return the lines that do not match, with the reason for each.
- You see which flagged differences are attributable to the exchange rate rather than the agreed price.
You'll meet Alexandre de PerregauxCEO & Founder, Intellyse
