Written by: Jordy Henraat, Freight Forwarder at Claassen Logistics
The customs process is quite prone to errors. One small misstep and the shipment comes to a standstill—sometimes for a day, sometimes even a week—all while your customer is waiting for the shipment. That’s why we asked our customs specialists at Claassen where things most often go wrong in practice. In this article, we share the 9 most common mistakes in customs export and import clearance.
Customs clearance is often seen as something the freight forwarder handles. That’s largely true. But the information provided by the shipper plays a major role in determining whether a shipment goes smoothly or gets held up. Claassen handles daily customs-cleared shipments to countries such as Norway, Switzerland, and the United Kingdom.
We see the same mistakes happening over and over again. When exporting outside the EU, even the smallest details matter.
Error 1. The "Sold-to" and "Ship-to" fields are mixed up on the invoice
This is a mistake we frequently encounter in practice, and it causes far more problems than people expect. The situation: a sale is made to Party A, but the goods are physically shipped to Party B—such as a distribution center, a subsidiary, or the end customer. If the invoice does not reflect this correctly, customs will not understand the transaction.
Customs wants to understand the exact sequence of events: who is the seller, who is the buyer, and where are the goods going? If the “sold to” and “ship to” details are not both clearly stated on the invoice, or if the invoice only lists the final destination without naming the commercial buyer, confusion arises. And confusion leads to an audit.
How to prevent this?
Make sure your commercial invoice always lists both the “sold-to” party (the buyer) and the “ship-to” party (the delivery address). Are these different companies in different countries? If so, state that explicitly. A good freight forwarder will verify that the transaction structure matches what is listed on the invoice.
Mistake 2. Not communicating the purpose of the shipment (correctly)
Customs doesn't just look at what is being exported or imported, but also the purpose of the shipment. Is it for sale? For use in production? For repair and return? Or temporarily, for a trade show or demonstration?
That distinction makes a big difference. When goods are exported for permanent sale, import duties and VAT are often paid upon customs clearance. However, those who temporarily export goods (and thus eventually re-import them)—for example, for repair, inspection, or processing—can often take advantage of special customs procedures.
If you do not specify the purpose of the shipment, you may end up paying unnecessary import duties or VAT.
How to prevent this?
Always consider the logistical and tax destination of the goods before shipping. Discuss this with the freight forwarder.
Mistake 3. Is customs export and clearance really necessary?
Not every shipment entering or leaving the EU needs to be cleared for import or export immediately. Many companies automatically assume this is the case, but it can result in unnecessary time and expense. Sometimes , customs procedures such as transit or storage in a customs bonded warehouse are a better alternative.
With a T1 transit, goods are transported under customs supervision, without import duties. This is useful, for example, when the goods pass through a non-EU country such as Switzerland.
A customs warehouse works differently: we store the goods under customs supervision, without any duties or VAT being due. Payment is only due upon actual import or export. Claassen has its own customs warehouse in Tilburg, which makes this a practical solution.
How can this be prevented?
It’s very simple. Always ask the freight forwarder: Is customs clearance required here, or is there a more suitable arrangement? They’re in the best position to advise you.
Error 4. Errors on the commercial invoice
The commercial invoice is the document where most errors occur. These are the areas where we most often see mistakes.
Incorrect or missing HS codes
The HS code determines the import duty rate. If you use a code that is too vague or outdated, customs will classify the goods on its own. That doesn’t always work out in your favor. If you use the same code that applied to a similar product ten years ago, you may end up facing reclassification.
Incorrect customs value
The customs value is not always equal to the invoice price. Depending on the Incoterms (terms of delivery) and the costs included in the sales price, expenses such as transportation, insurance, and other relevant costs (including, for example, royalties and licensing fees) must be included in the customs value, either in full or in part. An incorrect calculation can lead to an inaccurate customs declaration, incorrect assessment of import duties, and delays in customs clearance.
Country of origin
Many companies focus on the HS code but overlook the country of origin. Yet it is precisely the combination of the two that determines which import duties apply and whether additional measures are in effect—such as sanctions, antidumping duties, or product restrictions. Due to current geopolitical developments, these matters are being monitored more closely than ever. Products from certain countries may require additional documentation or may not be allowed to be imported at all.
Wrong currency
The invoice is in dollars, but the tax return is filed in euros. And the exchange rate? Nobody included it. Or the currency is listed inconsistently. A small mistake, but with major consequences during an audit.
Incorrect gross/net weights
It may sound trivial, but customs uses weight as a factor in risk assessment and as a means of verification. If the weight on the invoice differs from the packing list or the CMR, an inspection will follow.
Description of goods is too vague
Descriptions such as “machine parts,” “goods,” or “components” are often insufficient for customs officials. They also use the description of the goods to verify that the HS code is correct. It is also used for risk assessment. The more specific the description, the lower the likelihood of additional inspections.
How can you avoid this?
Be sure to check carefully that you’re using an invoice template that meets all customs requirements. Claassen offers a free sample commercial invoice that shows you at a glance how to fill out each field correctly.
Mistake 5. Incoterms Not Properly Agreed Upon
Incoterms specify who is responsible for transportation, risk (and, consequently, whether or not to arrange insurance), and customs formalities. But in practice, they are too often carried over from a previous order or not discussed with the buyer or freight forwarder. Two situations we regularly encounter:
EXW for exports outside the EU
EXW (Ex Works) sounds simple. The goods are made available, and the buyer is responsible for the export formalities. However, in practice, this often causes problems when exporting outside the European Union, because under European customs legislation, the exporter must generally be established in the EU for customs purposes. A buyer outside the EU cannot fulfill that role. The result: no export declaration, no proof of export, and no zero VAT rate. That creates a tax problem for the seller.
DDP with no clarity on VAT
Under DDP (Delivered Duty Paid), the seller pays the import duties. But does that also include import VAT? This is by no means always clearly agreed upon. The VAT rate can be 9% or 21%—that’s not an amount you want to be surprised by later.
With DDP, it must be clear in advance how import VAT will be handled and who is considered the importer for tax purposes. This is precisely where problems regularly arise in practice.
How to avoid this?
Discuss the Incoterm with the freight forwarder before it is agreed upon with the customer. This prevents a lot of confusion, especially with customs-related shipments. At Claassen, we therefore review in advance whether the chosen Incoterm is appropriate for the shipment and the agreements in place. Want to learn more about Incoterms in 2026? Here you can read all about Incoterms and how they work in practice.
Error 6. No declaration of origin or an incorrect declaration of origin
The origin of goods determines whether a preferential tariff applies, and that can make the difference between 0% and a substantial import duty rate. The correct document depends on the destination and the value of the shipment: an EUR.1 certificate, a statement of origin on the invoice, or a REX declaration.
In addition, the origin of goods is playing an increasingly important role in sanctions legislation and product restrictions. Certain countries or product groups may be subject to additional regulations, such as sanctions, import restrictions, or extra inspections. Examples include wood, metals, or products containing environmentally harmful substances. An incorrect or missing declaration of origin can therefore not only result in an incorrect import duty but also lead to delays or even the detention of a shipment.
What we often see in practice is that the statement is missing entirely. The text deviates from the prescribed wording. Or a document refers to a purchase invoice that has not been attached.
When exporting to the United Kingdom after Brexit, a Statement of Origin is often used for shipments valued at over €6,000.
EU exporters generally need a REX registration for this purpose.
How to prevent this?
For each destination, check which declaration of origin is required, whether the product complies with the rules of origin, and whether any additional sanctions or product restrictions apply to the country of origin. A good freight forwarder will verify this for you. When shipping to the UK, don’t forget the REX declaration if the shipment value exceeds the threshold.
Error 7. Reverse charge not arranged or incorrectly applied
Import VAT does not always have to be paid immediately at the border. With an Article 23 permit, the VAT can be deferred until the periodic VAT return. This offers a significant advantage. However, the permit must be in place and correctly applied in the return.
One thing we sometimes see go wrong is when an importer does not have an Article 23 permit but still assumes that VAT will be reverse-charged. We also see situations in which an Article 23 permit is not applied correctly or where the conditions are no longer met.
How to Avoid “
” Check in advance whether the recipient has a valid Article 23 permit. Any doubts? Discuss this with the freight forwarder or tax advisor before the shipment departs. Claassen is happy to assist you with this.
Error 8. Missing packing list
Technically speaking, a packing list isn’t always required, but in practice it’s indispensable. This is especially true for shipments consisting of multiple packages, mixed products, or pallets that are partially destined for different recipients. Without a packing list, customs cannot quickly verify the contents of the shipment, which increases the likelihood of a physical inspection.
We also regularly find that the packing list doesn't match the invoice. Different quantities, different descriptions, different weights. Naturally, that immediately raises suspicions.
How to prevent this?
Always provide a packing list, even if it’s not required. Make sure all the information matches the invoice and the shipping document. And always be well-prepared when shipping pallets.
Error 9. Failure to declare transit when transiting through non-EU countries
Goods traveling through Switzerland, Norway, or another non-EU country require a transit document. This is usually a T1. Without this document, the goods are considered imports upon entry, subject to the corresponding duties.
A common scenario we encounter regularly: the transit declaration is filed upon entry, but the exporter forgets to file the exit declaration on the other side of the border. The result? A back tax assessment that no one saw coming.
How to prevent this?
Have the freight forwarder handle the entire transit procedure, including the deregistration. For international shipments through Switzerland or other non-EU countries, this is not an option but a requirement.
Conclusion? Start before you leave
Most problems with customs clearance and export arise even before the truck hits the road.
That’s exactly why preparation is key. With the right customs documents, clear agreements, and an expert keeping an eye on things. Do you have a shipment outside the EU coming up soon and want to make sure everything is in order? Get in touch and make sure it’s all taken care of.
