From October 1, tourists from the 41 visa-exempt countries may still enter Thailand without visas and stay for up to 30 days, but they will only be able to extend their stay here two times - that is, for a maximum of 90 days.
And tourists who stay for 90 days must leave the Kingdom for at least 90 days before being permitted to re-enter Thailand.
The move is expected to have a big impact on the foreign community and some sectors such as teaching and diving, plus places where there are many bars run by foreigners, such as Pattaya and Chiang Mai.
But new rules have been issued because an increasing number of tourists have stayed for extended periods - without paying proper amounts of tax. This has also helped them avoid close scrutiny by authorities here and in their homeland.
"We are trying to make it more difficult for bad people to get in," Immigration Police chief Lt General Suwat Thamrongsrisakul said at a press conference yesterday.
"I don't think it's going to hurt good people because they can apply for a tourist visa," Mr. Thamrongsrisakul said.
Thailand recently simplified the process for foreigners who want to become permanent residents. The amount of paperwork required has been slashed and the time involved reportedly cut from more than a year to about four months.