The Customs Department estimates that tax revenue collection will fall 4.5 billion baht short of the 105-billion-baht target for this fiscal year, due to a string of tax reductions from free trade pacts.
The latest free-trade agreement with China for tile products, for example, results in a tax revenue loss of 220 million baht a year, said director-general Kulit Sombatsiri.
The Customs Department failed to achieve its tax revenue target in recent years, missing the target by 2.2% in fiscal 2013, 17.4% in 2014, 5.6% in 2015, 7.4% in 2016 and 13% in the last fiscal year.
The tax-collecting agency gathered revenue of 113 billion baht in fiscal 2013, 108 billion in 2014, 115 billion in 2015, 111 billion in 2016 and 104 billion last year.
Mr Kulit said the department is seeking solutions after importers and exporters complained that they cannot comply with new legislation that requires the re-export of cross-border goods within 30 days, down from 90 days previously.
There are several options to tackle the problems, including storing cross-border imports in tax-free zones, but exporters are required to show evidence as to why they cannot ship these products within the prescribed period, Mr Kulit said, adding that those who order cross-border imports typically must have sales orders in hand.
The amended Customs Act 2017, which went into force on Nov 13 last year, helps reduce several import obstructions for more convenient processes for businesses, such as the adoption of the pre-arrival processing system.
With the new system, goods shipped by sea or air can be discharged from customs immediately upon arrival if they are not listed as risky products, compared with 5-7 days previously.
The new system requires all cargo ships to send a digital manifest to the Customs Department within 24 hours after they depart exporting countries, while airlines must send a digital manifest to the department immediately after take-off.
The Customs Department evaluates the risks of imported goods and importers' history, employing big data analytics.
Separately, Mr Kulit said the Customs Department has amended regulations requiring products imported to the free-trade zone of the Eastern Economic Corridor to ask for documents from related state agencies.
Under the new regulations, imported raw materials for manufacturing exports no longer need to ask for such documents, but those importing to produce goods for domestic consumption still need them.