It found many cases of value-added tax evasion with exporters buying directly from farmers and not reporting the transaction to tax authorities.
Some companies owners would establish "intermediary companies" which often report small revenues to authorities, but the main export firm that sources inputs from these companies often buy large orders from them.
After inspecting 120 intermediary companies, the department has found 92% of them having suspended operation to avoid paying taxes.
The tax department also said that refunding tax to some businesses faces challenges as in many cases the foreign companies inspectors contacted said they never sold good to the Vietnamese company that is seeking a tax refund.