Recent large swings in fuel prices have created significant market volatility

Unusual signals from e-invoice data

Since the beginning of 2026, global geopolitical developments, particularly in the Middle East, have remained complex, raising the risk of disruptions to crude oil supply. This has pushed global oil prices sharply higher, leading to ongoing fluctuations in domestic fuel prices. In March 2026 alone, Vietnam adjusted retail fuel prices five times, reflecting the market’s sensitivity and unpredictability.

Against this backdrop, data from the e-invoicing system has begun to show unusual patterns. Reviews by tax authorities indicate that at several fuel trading companies, sales volumes rose sharply before price adjustments, in some cases reaching levels several times higher than immediately after prices were revised.

These irregular movements raise questions about whether businesses are using price differences to manage sales volumes and maximize profits. At the same time, practices such as issuing invoices at incorrect times, failing to reflect the true nature of transactions, or underreporting revenue may occur, posing significant risks for tax administration.

Calls to tighten discipline in the fuel market had already been issued in earlier government directives.

Under Official Dispatch 2389/VPCP-V.I dated March 19, 2026, issued by the Government Office on combating smuggling and trade fraud in fuel trading, government leaders instructed ministries, agencies, local authorities, and enforcement forces to closely monitor market developments, assess supply and demand, and track price movements to ensure timely and appropriate policy responses.

In particular, relevant forces, including customs, tax authorities, border guards, the coast guard, market surveillance units, and the police, have been directed to step up patrols and inspections; promptly detect and prevent smuggling, trade fraud, speculation, hoarding, policy abuse, and other violations in fuel trading activities. Stronger inter-agency coordination, information sharing, and strict enforcement in line with legal provisions are seen as key measures to maintain market stability amid ongoing price volatility.

Aggressive inspections and tax enforcement

In carrying out these directives, tax authorities have instructed the sector to focus resources on reviewing and analyzing data related to fuel trading activities, with particular attention to sales volumes, revenue, inventory levels, and e-invoices during price-sensitive periods.

Accordingly, businesses showing high-risk indicators will be subject to surprise inspections. These inspections will focus on the declaration and payment of value-added tax, environmental protection tax, and compliance with the requirement to issue e-invoices for each transaction, a mandatory measure to ensure transparency.

A key step is the close matching of e-invoice data with accounting records, inventory receipts and dispatch documents, and actual stock levels. Daily and shift-based inspections are expected to give a clear view of product flows, helping detect discrepancies in a timely manner. In addition, unusually large fuel transactions will be reviewed carefully.

When violations are identified, enforcement measures will be applied strictly in line with regulations, including the collection of tax arrears, administrative penalties, or referral to competent authorities in cases showing signs of criminal violations. This sends a clear signal to strengthen deterrence and ensure that all violations are detected and handled promptly.

Stricter tax management, combined with digital tools such as e-invoicing and big data analytics, is expected to improve oversight efficiency and support a more transparent and fair market. This also reflects the broader direction of tax sector modernization, aligned with the demands of a digital economy.