One of the challenges in applying risk management techniques to the cross-border flow of goods bought online is the quality of the data. This is a concept which, as set out in the WCO–UPU Guidelines on the Exchange of EAD and Data Quality, refers to:

• Timeliness: data should be transmitted to Customs prior to arrival where they have electronic interfaces, enabling effective pre-arrival risk assessment.
• Accuracy: data should accurately represent the physical content of the consignment.
• Completeness: all mandatory data elements – such as HS codes for commercial items, where required, should be included to ensure full Customs compliance.
• Consistency: data should conform to structured formats, shared definitions and agreed protocols, so that it is interpreted uniformly by all stakeholders.

Postal operators and Customs administrations can solve issues related to data consistency and efficient electronic data exchange by using the WCO Data Model and the joint WCO–UPU Message Standards which enable Posts to exchange data contained in CN 22 and CN 23 forms -the Customs declarations for international mail, via electronic data interchange.

However, ensuring data accuracy and completeness remains a challenge, especially when data is provided by individuals and not business customers. Identified persistent problems include vague description of goods, such as “gift”, “parts” or “clothes”, unrealistic values such as “0” or “1”, or incorrect or incomplete address information. The exemption of Customs duties on certain goods sent by a private person as a gift is also sometimes wrongly claimed with senders declaring commercial goods as gifts. This leads to unnecessary physical inspections, and delays in clearance.

Against this background, a number of initiatives have been implemented to improve data accuracy and completeness.

Two important changes were recently made to the postal Customs declaration forms, namely the CN22 – packages under 2 kg in weight -, and the CN23 – packages over 2 kg or where the customs declaration does not fit in the space available on the CN22. Senders must provide brief details of the origin, classification and Customs value of the goods. The main difference between the two forms being that the CN23 allows for the provision of additional information such as whether import certificates or licenses are enclosed, as well as additional details of the sender and the importer (e.g. tax, customs reference). Senders are also required to declare the category of the item (e.g. “Documents”, “Returned goods”, “Gift”, “Other”). From 1 June 2026, senders will be able to select from an improved list of categories which now includes “E-commerce goods”, “Commercial sale of goods (B2B)”, and “Gift (non-commercial)”. Moreover, from 1 September 2025, the six-digit WCO Harmonized System (HS) tariff codes are mandatory for commercial items if the destination country so requires.

The designated postal operator’s role is to act as facilitator, assisting customers in providing electronic Customs declaration data by offering them tools, application programming interfaces (APIs) and applications, in order to gather quality declaration data and ensure compliance with the Customs declaration forms.

AI-driven solutions have been developed to support data quality improvements by enabling automated data validations, issuing error messaging to guide data providers, assisting them in identifying prohibited goods and providing standardized and complete address data.

The UPU has developed an address verification tool called POST*CODE API which provides real-time address data capture, and auto-complete suggestions for locality names, postcodes and locality verification as well as postal code structure validation ensuring adherence to national formats and ITMATT compliance. At present, postal operators in around 130 countries rely on this tool as part of their addressing systems.

The tool can be used independently with any application that captures international addresses, as well as a plugin with the Customs Declaration System (CDS), a solution developed by UPU Postal Technology Centre to streamline the submission and exchange of EAD using global electronic data interchange (EDI) message standards (such as ITMATT, CUSITM, CUSRSP). The CDS is currently used by 174 designated postal operators of UPU member countries.

The latest CDS release (2024 Service Pack 1) also brings built-in connectivity into lookup tools which assist users in identifying restricted or prohibited items and finding correct HS codes. It also helps users see whether a potential buyer, end-user, or any party involved in the transaction, is safe to engage with in business by integrating denied party lists.

Business customers are usually familiar with commercial and regulatory requirements regarding the goods that they are sending. Normally, they have the means, capacity, tools and resources to obtain the declaration data elements needed.

Individual customers who send personal effects, occasional gifts or goods for private use are generally not very familiar with all the data elements required when filling in the forms, which have been digitalized in most designated postal operators of UPU member countries. Many postal operators have doubled efforts to inform individuals by introducing mobile apps (like the UPU EAD App), providing clear instructions on their websites, deploying physical data-entry kiosks in their premises, or training their staff to educate and guide customers visiting their offices

The WCO and UPU have been encouraging Customs administrations and designated postal operators to formalize their cooperation through Memorandums of Understanding (MoUs) at the national level and have developed guidelines in this regard. Such agreements provide a framework for collaboration in line with the provisions of the Revised Kyoto Convention, Specific Annex J, Chapter 2 on Postal Traffic, as well as the Acts of the Universal Postal Union. They may set out the respective roles and responsibilities of each party in relation to the verification of CN22 and CN23 declarations provided by the sender, the establishment of feedback mechanisms to address recurring data quality issues, and the arrangements for risk assessment making effective use of electronic advance data.

MoUs can also define standards and procedures for the electronic exchange of information, drawing on the WCO–UPU Message Standards (ITMATT, CUSITM and CUSRSP) and the WCO Data Model, thereby promoting consistency and interoperability across the global postal supply chain. In addition, they may establish measurable performance indicators to monitor the quality of the data provided and to support continuous improvement. By incorporating these elements, MoUs help ensure that Customs and Posts work in close partnership to achieve their shared objectives of secure, efficient and reliable clearance of postal items, underpinned by accurate, complete and timely data.

More information
UPU Customs Declaration System
WCO UPU Postal Customs Guide
WCO-UPU Guidelines for developing a Memorandum of Understanding between Customs and Post at national level
Joint WCO-UPU Guidelines on the Exchange of Electronic Advance Data (EAD) and Data Quality