When customs audits occur at EPE factories in Vietnam, the biggest fear for the finance and warehouse staff isn't discrepancies in the numbers, but rather "not knowing where to begin reconciling them." Import registration is in one system, material requisition records are in another, and waste disposal is presented in yet another Excel spreadsheet—these three data sources are not interconnected, making each audit a manual jigsaw puzzle.

The fundamental problem of discrepancies between accounts and actual data is often not that employees are not diligent, but that the three data segments in the process design do not have a closed loop. The key is to make three key settings.

The first setting: Material receiving record directly linked to BOM.

Each batch of imported raw materials has a corresponding customs filing. The product in which this batch of materials will be used and how much will be consumed should be linked to the BOM (Bill of Materials) in the system at the time of filing and login, rather than manually matching it afterward.

The practical significance of doing this is that when inspectors ask, "Where did this batch of imported materials go?", the system can directly provide a complete traceability path from registration to production work order without the need for temporary organization.

In practice, two prerequisites need to be confirmed: First, the import registration must be entered into the system on the day the materials arrive, and batch registration is not allowed; second, the material specifications in the BOM must be consistent with the material number declared in the registration, otherwise, although the system is bound, the offsetting numbers will still not match.

The second setting: Production material requisition triggers automatic write-off of bonded inventory.

Many EPE factories manage both bonded inventory and general inventory in their ERP systems, but the deductions for the two are often done separately. When materials are requisitioned for production, the system deducts the general inventory, but the bonded inventory ledger needs to be updated manually. If even one entry is forgotten, discrepancies will occur.

The correct operating procedure should be: when a production work order issues a material requisition instruction, the system should automatically identify the bonded attribute of the batch of materials and deduct the corresponding bonded inventory balance. This automatic triggering mechanism requires data connection between systems. If the systems operate independently, it is necessary to confirm whether the data has been integrated.

Once this setting is configured, the bonded inventory ledger will change from "manually updated" to "synchronously completed during production operations," allowing for direct access to system records during audits, rather than rebuilding the ledger afterward.

The third setting: Early warning of differences in waste loss rate

Waste and process losses at EPE plants are high-risk areas for customs inspection. According to Vietnamese customs regulations, the amount of imported raw materials used must match the quantity of the final finished products exported. Any discrepancies exceeding the registered loss rate must be explained or additional customs duties must be paid.

The key to setting up an ERP system is to establish standard loss rates for each product within the system and to automatically issue an alert when actual losses exceed a threshold, requiring on-site personnel to submit a discrepancy report. This alert mechanism allows discrepancies to be recorded as soon as they occur, rather than waiting for an audit to arrive before retrospectively addressing them.

The standard loss rate needs to be set based on the actual process. Setting it too leniently will render the warning meaningless, while setting it too strictly will cause frequent interruptions on-site. It is recommended to set it based on historical data initially, and then calibrate it after running for three months.

Two prerequisites that need to be confirmed before the system is deployed

Whether the above three settings can be effective depends on two basic conditions. The first is the timeliness of data entry: import registration, material requisition records, and waste declarations must be entered into the system immediately, rather than being added at the end of the month or before the audit; otherwise, the automatic offsetting logic cannot operate.

Secondly, there's the issue of BOM accuracy: if the actual formula or material specifications used on the production floor differ from the BOM in the ERP system, the consumption calculated by the system will create a structural discrepancy with the recorded figures. This isn't a setup issue, but rather a data management issue, requiring prior cleanup before importation.

The automation of EPE bonded ledgers essentially integrates data flows scattered across different stages into a traceable logic. Each of the three settings addresses a breakpoint in a process, and together they transform the ledgers from "rushed preparation before audits" into "a natural output of daily operations."

Further Reading

New regulations for Vietnam's EPE export processing enterprises in 2026: tightened bonded supervision, and a compliance list that foreign-invested factories must complete.

Vietnam Tax Audit Trends 2026: Transfer Pricing and Related-Party Transactions Become Key Audit Focuses; How Can Foreign-Invested Enterprises Protect Themselves?

From WMS to Smart Warehousing: Upgrading Warehouse Management in Vietnam's Manufacturing Sector