A new United States Postal Service rule places the financial and legal responsibility for certain foreign customs charges directly onto American merchants who sell products across international borders.
Taking effect on October 19, the regulatory change establishes formal procedures for collecting or reimbursing unpaid foreign duties, taxes, and import fees. Under the framework, the USPS—acting either directly or through a third-party representative—will issue bills directly to merchants in situations where certain foreign customs fees remain unpaid, or when a foreign entity actively seeks payment for a delivered or processed shipment.
The shift fundamentally alters how cross-border ecommerce operates for domestic sellers, introducing potential financial liabilities that can materialize long after a package has crossed an international border, been delivered to a consumer, or even been returned to the sender.
Responsibility
The scope of the new postal rule is broad, covering standard duties and taxes alongside potentially more expansive fees imposed by foreign customs agencies, national postal operators, independent customs brokers, and various other international logistics service providers.
If any of these authorized parties report an unpaid charge associated with a shipment, the USPS is now empowered to invoice the original shipper, a role traditionally referred to in postal terminology as the "mailer."
This does not mean that every single U.S. merchant sending an international package will automatically receive a bill. The ultimate responsibility for customs charges depends heavily on the specific regulatory requirements of the destination country, as well as the chosen shipping method. However, the policy means that additional costs can now materialize long after an international delivery has seemingly been completed and finalized.
While alternative private carriers like UPS and FedEx operate under their own commercial terms, all major logistics providers must ultimately ensure that applicable import charges are paid to clear customs. Consequently, switching commercial carriers does not necessarily eliminate the underlying risk of unexpected fee assessments.
Europe
The USPS explicitly linked the implementation of this new rule to the structural policy changes brought about by the July 2026 elimination of the European Commission’s longstanding de minimis exemption. As a direct consequence of that policy shift, import duties and handling fees now apply to low-cost merchandise entering Europe that would previously have been entirely duty-free.
To manage this massive influx of low-value commercial imports, the European Union implemented a temporary, non-refundable flat fee of three euros—equivalent to approximately $3.36 USD—for each unique Harmonized System Code product type contained within a shipment. This standardized classification system is widely utilized by both European authorities and global customs agencies worldwide.
Under this temporary E.U. framework, a commercial parcel containing three separate items that all share the exact same Harmonized System classification will be assessed a total duty of three euros. Conversely, if a parcel contains products spanning two different Harmonized System classifications, the total temporary duty for that single parcel doubles to six euros.
European Union authorities have indicated that this temporary flat-fee duty structure will remain in effect through June 30, 2028, by which time more permanent, comprehensive processing procedures are expected to be fully established and integrated.
However, the reach of the new USPS invoicing rule is not limited exclusively to Europe. The regulatory framework applies globally, affecting shipments sent to various international jurisdictions with evolving digital trade and customs enforcement mechanisms.
Dispute Later
Perhaps the most consequential and controversial aspect of the new postal rule is that merchants are required to pay the USPS invoice even while actively disputing an underlying, potentially incorrect assessment.
The USPS has clarified that it is not responsible for determining whether a foreign customs authority, foreign postal operator, or any other external entity calculated its assessed charge correctly. Instead, if a merchant believes an error was made, they must pursue the matter independently with the specific foreign entity that issued the assessment.
Furthermore, a failed or aborted shipment does not necessarily eliminate the financial liability. The rule explicitly states that the shipper remains fully responsible for all applicable charges regardless of whether the physical parcel is successfully delivered, lost in transit, damaged, or ultimately returned to the merchant.
Consider a hypothetical scenario where a U.S. merchant ships a $100 order to a customer in France. Upon arrival, the customer declines to accept the package because of an unexpected local customs charge, and the merchant dutifully issues a full refund to the customer upon receiving the returned product.
Under the new postal rules, that merchant could still find themselves legally owing the unpaid foreign customs charge, complete with accumulating interest. Past-due USPS invoices associated with these international fees accrue interest at an annual rate of 6%.
DDP
One established method for merchants to reduce uncertainty and avoid post-delivery surprise bills is to utilize the USPS Delivered Duty Paid service for eligible international shipments and destination countries.
By opting for DDP, a merchant can obtain an upfront cost quote and prepay all applicable duties, taxes, and handling fees at the exact moment they purchase their international postage. The service is currently available for shipments directed to 18 distinct countries, including major trading partners such as Canada and the United Kingdom.
While the USPS itself does not charge an additional fee for utilizing the DDP framework, its designated third-party technology provider, Zonos, incorporates a service fee directly into the upfront calculation quote.
While a DDP quote may not always serve as an absolute ceiling in every complex regulatory environment, it significantly reduces the risk of unexpected, retroactive charges. Conversely, sending international parcels without prepayment where permitted may leave crucial cost components unresolved until the package physically reaches its foreign destination and encounters local customs scrutiny.
After Delivery
Global merchants, including thousands of businesses operating across the United States, have long managed international duties and taxes, working to clearly explain these cost structures to their buyers. That operational reality is not entirely new.
The new USPS rule, however, injects a critical layer of financial risk, providing merchants with yet another reason to treat these international fees as an integral component of the initial sale rather than treating them strictly as the customer’s individual problem.
Consequently, a merchant selling a low-margin product across international borders may need to carefully account for potential unpaid shipping and customs costs in their baseline pricing strategies. Returned, refused, or undelivered orders could prove particularly costly because international customs liability can legally survive long after the corresponding product revenue has vanished.
This regulatory change could also fundamentally alter how ecommerce merchants utilize enterprise shipping software systems, calculate complex landed costs, establish rigid country-specific shipping policies, and account for the financial burden of international returns.
While the text of the rule itself does not specify the exact mechanisms or formats by which these retroactive invoices will ultimately arrive, the practical implication for merchants is clear. International orders now carry a lingering, shipping-related financial liability that can follow a business long after the delivery window has closed, even for goods that are ultimately sent back.
