The government is considering introducing a tax on share sales by individual investors on the Stock Exchange of Thailand (SET) to generate additional revenue, three sources familiar with the matter told Reuters.
Officials are studying the possibility of ending a tax waiver, which has been in place since 1991, on securities sales on the SET, two sources said.
The tax of 0.11% on equities sales would apply to investors with a volume of more than one million baht per month, a source said.
"The government wants to find ways to generate more revenue, but this plan could spook investors," the source said.
The idea is similar to a Tobin tax that is applied on financial transactions akin to those in India and Taiwan.
The Thai bourse did not respond to a request for comment.
"It's part of the government's tax reform agenda," another source familiar with the matter told Reuters, adding the proposal was only in the preliminary stages.
They are just studying the impact and weighing benefits and costs, the source said.
"When you look at tax reform, you have to look at everything in the country."
The plan was to collect tax from the wealthy and was only at a conceptual stage with no time frame, a third source said.
The government currently collects a capital gains tax from local and foreign institutions, but individual traders are exempt. The main stock index is up 9% this year.
Authorities have studied the possibility of a capital gains tax on individual investors in the past.
The government did not immediately respond to a Reuters request for comment.