Online traders must display prices and details of products and services or risk being fined, the government has warned.
Nuntawan Sakuntanaga, director-general of the Internal Trade Department, said the Royal Gazette recently published the announcement of the central commission on prices of goods and services signed by Commerce Minister Apiradi Tantraporn.
The new regime aims to give consumers a choice in comparing the prices of goods and services before making a decision to buy the products or use the services online.
Online traders are also required to display details about service charges, delivery charges and product characteristics, size and weight in writing or print on the products and for services in Thai or foreign languages.
In case there are any expenses in addition to the prices of products and services, online traders and operators need to display such expenses clearly on a transparent basis.
The announcement came into force on Jan 25.
According to Ms Nuntawan, online traders who fail to comply with the announcement will be subject to a 10,000 baht fine.
In a move to protect online shoppers, the Commerce Ministry in January added delivery charges for online shopping and counter services to the list of expenditures that need special supervision by state officials, or the price control list, due to growing usage.
According to research jointly conducted by PayPal and Paris-based market researcher Ipsos, the number of online shoppers in Thailand reached 7.9 million last year, with 2 million purchasing goods from overseas websites.
Thailand's e-commerce spending is predicted to increase by 16% to 377 billion baht in 2017 and 426 billion in 2018 from about 326 billion in 2016.
Thailand's online cross-border shopping is expected to grow by 84% this year from 60 billion baht in 2016 as users gain confidence in online channels and seek certain products unavailable domestically, according to PayPal, the US-based digital payments giant.
Online cross-border shopping by Thai users purchasing products from overseas websites has been found to have grown much more than the country's overall e-commerce market, which combines the business-to-business and business-to-consumer segments.
Thailand is the third Southeast Asian country where PayPal has chosen to open a local office, after Singapore and Malaysia.
The price control list covers essential items for daily use such as food, consumer products, farm-related products (fertilisers, pesticides, animal feed, tractors, rice harvesters), construction materials, paper, petroleum and medicines.
Listed foods include garlic, paddy, milled rice, corn, eggs, cassava, wheat flour, yoghurt, powdered/fresh milk, sugar, vegetable/animal oil and pork.
Consumer products include detergents, sanitary napkins and toilet paper.
Businesses making or selling listed products are required to inform the authorities of production costs and seek approval for price increases.