The Centre for Covid-19 Situation Administration's (CCSA) operation centre has agreed to lift capacity limits on domestic flights, allowing airlines to take full flight bookings, according to the Public Health Ministry.
The number of passengers was previously limited to 75% of the full capacity.
Dr Chawetsan Namwat, director for emergency health hazards and diseases, said that while airlines are allowed to book to full capacity he stressed other Covid-19 prevention measures remain intact.
These measures include a ban on in-flight drinking and eating, the need for a good ventilation system and proper social distancing on boarding and leaving aircraft, he said.
Dr Chawetsan said that passengers are required to be fully vaccinated or have negative Covid-19 test results 72 hours before boarding while urging those who are ill to avoid travelling.
He said passengers will be required to undergo Covid-19 screening.
He said social distancing measures and personal hygiene must be strictly observed by the public following the easing of the Covid-19 restrictions to prevent a rebound.
Antigen test kits (ATK) are also effective tools in Covid-19 screening for the public to use, he said.
Meanwhile, the International Air Transport Association (IATA) reported that air travellers are increasingly frustrated with Covid-19 travel restrictions.
A survey commissioned by IATA of 4,700 respondents in 11 markets in September demonstrated confidence that the risks of Covid-19 can be effectively managed and that the freedom to travel should be restored.
Of respondents, 67% felt that most country borders should be opened now, up 12 percentage-points from the June 2021 survey.
About 64% of respondents felt that border closures are unnecessary and have not been effective in containing the virus (up 11 percentage points from June 2021).
Some 73% responded that their quality of life is suffering as a result of Covid-19 travel restrictions (up 6 percentage points from June 2021).
"People are increasingly frustrated with the Covid-19 travel restrictions and even more have seen their quality of life suffer as a result," said Willie Walsh, IATA's director general.
"They don't see the necessity of travel restrictions to control the virus," Mr Walsh said.
"And they have missed too many family moments, personal development opportunities and business priorities."