USPS Can Bill Sellers for Foreign Duties: What Merchants Should Do

A returned international order can leave a seller with more than a lost sale. Under a new U.S. Postal Service rule, the USPS can bill a merchant for certain foreign customs charges that remain unpaid, even if the parcel never reaches the customer.

The rule took effect on October 19, 2026. It applies to U.S. merchants shipping internationally through USPS, but the underlying risk is relevant to any business selling across borders: customs costs may not be settled when a customer places an order or receives a parcel.

The Practical Ecommerce report on the USPS rule explains who may receive a bill and what the change means. For merchants, the practical task is to bring duties and import fees into pricing, shipping choices and customer communication.

What the USPS rule changes

The USPS has set procedures for collecting or reimbursing foreign duties, taxes and import fees. If a foreign customs agency, postal operator, broker or other service provider reports an unpaid charge, the USPS may invoice the shipper. In postal terminology, that shipper is the “mailer.” The USPS may send the bill itself or through a third-party representative.

This does not mean every U.S. merchant sending an international parcel will receive an invoice. Responsibility for customs charges depends on the destination country’s requirements and the shipping method. But a merchant may face a bill after delivery, rather than paying everything when postage is purchased.

The rule is not limited to Europe. The USPS linked it to the European Union’s decision to end its de minimis exemption in July 2026. Low-cost merchandise that had been duty-free can now incur fees. The rule establishes a way for the USPS to handle charges, while applying across countries and regions.

Switching from USPS to another carrier does not remove the underlying customs liability. The source notes that all carriers, including UPS and FedEx, must ensure those charges are paid. Businesses should therefore focus on how they price, collect and manage customs costs, not assume a carrier change will make them disappear.

Why returned orders can still cost you

The most important detail for cash flow is that a merchant must pay the USPS invoice even while disputing the original assessment. The USPS does not decide whether a foreign authority or service provider calculated a charge correctly. The merchant must pursue any dispute with the party that assessed it.

A shipment’s failure also does not necessarily end the merchant’s liability. The rule says the shipper remains responsible for applicable charges whether a parcel is delivered, lost, damaged or returned. That creates a risk when a customer refuses a package, a delivery fails, or a seller refunds an order after its return.

Consider the example in the source: a merchant ships a $100 order to a customer in France. The customer declines it because of an unexpected customs charge. The merchant refunds the order after receiving the product back, but may still owe the unpaid charge, with interest. A past-due USPS invoice accrues interest at 6% annually.

This makes international returns more complicated than reversing a product sale. A seller may recover the goods and refund the customer, yet still owe a separate shipping-related amount. For low-margin products, that cost can use up the remaining margin or add to the loss.

Businesses already selling abroad should review how their international plans fit a wider expansion strategy. The core lesson is to treat customs charges as part of the transaction’s economics, rather than assuming they are solely the customer’s responsibility.

Understand the European fee example

The European Union has introduced a temporary, non-refundable flat duty of €3.00 ($3.36) for each unique Harmonized System Code product type. Harmonized System Codes classify products and are used by the E.U. and worldwide authorities.

The fee is based on distinct product classifications in the parcel, not simply the number of items. Three items with the same HS classification mean a temporary duty of €3.00 in total. Products in two HS classifications mean a temporary duty of €6.00 for the parcel.

E.U. authorities say the flat-fee duty will remain in place through June 30, 2028, when permanent procedures will be in place. This is a specific E.U. arrangement. It should not be treated as the rate for every destination, or as evidence that every international order will be charged the same way.

For sellers, the example shows why product classification matters. If a store’s catalogue includes items that fall under different HS codes, the number of distinct classifications in a shipment can affect the duty. A product-level record that includes the relevant classification can help a business estimate costs more carefully and investigate a charge if it appears incorrect.

Make duties part of the selling process

One option for eligible USPS shipments is Delivered Duty Paid, or DDP. When buying postage, the merchant obtains a quote and prepays applicable duties, taxes and fees. The source says the service is available for shipments to 18 countries, including Canada and the United Kingdom.

The USPS does not charge for DDP, but its third-party provider, Zonos, includes a fee in the quote. The quote is not an absolute ceiling. Still, prepayment can reduce the chance of unexpected charges remaining unresolved until the parcel reaches its destination. Sending without prepayment, where permitted, may leave some costs unsettled.

DDP is not a substitute for checking the destination’s requirements or reviewing the quote. It is a way to bring known charges into the postage purchase. Before adopting it, compare the quoted cost with your product margin and shipping price, and decide how those costs should be shown to customers.

A practical review can include:

• Shipping policies: Explain whether customers or the business pay duties, taxes and import fees. Make the policy visible before checkout, not only after an order is placed.
• Landed-cost estimates: Review whether product prices and shipping charges account for destination fees. Check low-margin products especially carefully.
• Returns and failed deliveries: Decide how your business will handle a refused parcel, a refund and any customs charges that remain payable.
• Product records: Keep HS classifications and destination-specific shipping information organised. This helps with estimates and with investigating a disputed assessment.
• Shipping tools: Check whether your shipping software can support the information and workflows needed for your chosen destinations. For teams working across multiple tools, automation and integrations may help connect relevant processes.

What to do next

Start by listing the countries you currently ship to and the shipping methods you use. For each destination, confirm how customs charges are handled and whether a prepaid option such as USPS DDP is available for eligible shipments. Do not assume that one rule or rate applies everywhere.

Then review a sample of your products and shipping prices. Identify products with tight margins, check their HS classifications, and consider how destination fees could affect a sale. Update your checkout and shipping policy so customers can understand potential charges before they buy.

Finally, write down what happens when an order is refused, lost, damaged or returned. Include who will review an invoice, how your business will challenge an incorrect assessment with the entity that issued it, and how quickly an invoice needs attention. The USPS rule makes one point clear: an international order can create a cost after the sale has ended. Planning for that possibility is part of selling across borders.