Carmakers have asked the Excise Department to declare the new excise tax in advance so they will have time to prepare for the levy before it comes into force on Sept 16.
The industry will this month submit a letter to the Finance Ministry calling on the Excise Department to reveal the levy before the new tax regime comes into effect, said Arnupab Tadpitakkul, chairman of the economics, regulation and tax working group at the Federation of Thai Industries.
The auto industry would prefer the government announce the new tax rate prior to its implementation, as was done for the current tax on vehicles based on carbon dioxide emissions, which was announced a few years before coming into effect, said Mr Arnupab.
"We hope the new tax rate will not affect investment plans or burden consumers," he said.
Importers of foreign cars, whiskey and wine have vented their mounting frustrations about Thailand's new excise tax law, saying it may bring about retaliatory measures from other countries.
The amended excise tax law changes the base for excise tax to recommended retail prices from the existing ex-factory prices and cost, insurance and freight (CIF) values.
The Excise Department hopes the recommended retail prices create a fairer system for makers and importers after was it found that some of them were exploiting the ex-factory and CIF values to understate their tax bills.
The act also authorises the director-general of the Excise Department to determine recommended retail prices for use as a base for excise tax calculation in the event of disputes. If the recommended retail price is not in line with the market price, the department will have the power to determine it, which will be based on retail market prices or import prices.
The department is drafting 80 organic laws to facilitate the new base for excise tax computation.
Meanwhile, Somdet Srisawat, deputy director-general of the Excise Department, said the department will consider moving up the new tax rate declaration as requested.
The nature of the auto industry requires it to make production plans long in advance, so it is necessary to know the new tax rate as soon as possible, he said.
The Excise Department recently said the organic laws would be announced by August.