The DIT has also forbid sellers via Facebook, Instagram, Line, websites, and other platforms to only reveal the price through private messages or personal calls.
Violaters will be fined up to 10,000 baht. Those who provide information on such practices will receive 25 per cent of the fine as reward, the department said.
The evidence could be in the form of chat messages, price in the private messages, and the bank account of the seller.
People could inform or report online sellers to the DIT on hotline 1569 or email at [email protected]