The Airports of Thailand board of directors has agreed on the need to raise the airport departure tax for both domestic and international passengers by 100 baht, AoT Chairman Sita Divari said on Thursday.
The departure tax for domestic flights would rise from 100 baht to 200 baht, and from 700 baht to 800 baht for international flights, Mr Sita said.
The increase still needs final approval from aviation and transport authorities.
The new fees would apply at all airports operated by AoT when approved.
The latest attack on tourists' wallets comes on top of the government's move to charge foreigners a new arrival tax at airports and land border crossings.
The government is considering a plan to charge foreigners a 500-baht entry fee from January next year. (Photo by Patipat Janthong)
On Sunday, Public Health Minister Pradit Sintavanarong said the government is considering a plan to charge foreigners a 500-baht entry fee from January next year. He claimed the extra charge would lead to an improvement in the quality of tourists entering Thailand.
It would also offset the costs of state hospitals treating tourists who have accidents or fall ill and have no insurance cover.
Foreigners who arrive at airports would be charged 500 baht while those who enter the country by land would be charged 30 baht a day.
The foreigner-entry charge has been widely criticised on web forums, by tour operators and people working in the hospitality industry.
Malaysian tourists are the latest group to complain.
Withaya Lim, a tour operator in Hat Yai, said many tour agencies and tourists from Malaysia had contacted him to complain after they learned of the entry charge plan.
"This will increase costs for tour agencies bringing people to Thailand and they will have to pass the cost on to their customers," Mr Withaya said.
"I'm afraid this will result in a drop in the number of foreign tourist arrivals, particularly from Malaysia, Singapore, Indonesia and Brunei."
According to the AoT, passenger traffic through Thailand's six main airports showed robust growth in the fiscal year to last month, climbing 20.4% from the previous year to 86.13 million travellers, both domestic and international.
The number of flights through these airports increased by 16.5% to 559,397 during the same period.
Suvarnabhumi, the country's gateway airport, continued to dominate traffic volume with 50.90 million passengers and 287,997 flights, accounting for 59% of overall passenger numbers and 51.5% of all take-offs and landings.
It was followed by Bangkok's second airport Don Mueang, which largely serves discount airlines, with 15.56 million passengers and 135,976 flights.
Phuket airport recorded 10.98 million passengers with 70,198 flights.
Chiang Mai had 5.17 million passengers and 41,295 flights, while Hat Yai had 2.47 million passengers and 17,056 flights, and Chiang Rai 1.05 million passengers and 6,882 flights.
Suvarnabhumi is served by 107 international airlines. The airport connects Bangkok with more than 150 cities around the world.
The top five nationalities of tourists arriving through Suvarnabhumi are Chinese, Japanese, Indian, South Korean and Russian.