The Thai Centre for Covid-19 Situation Administration has announced that interprovincial travel in the country, including to and from the highest-risk provinces, will be allowed again as of September 1, 2021.

Following the announcement, Thai VietJetAir and Thai Smile announced that they would resume all of their scheduled routes out of Bangkok Suvarnabhumi as of September 1. Thai Lion Air and Nok Air plan to gradually restart all of their respective domestic routes out of Bangkok Don Mueang on September 1, while Thai AirAsia said that it would restart 11 domestic routes out of Don Mueang on September 3. Flag carrier Thai Airways International does not currently operate any domestic routes but rather sustains itself on international charter and cargo-only flights.

Nearly all Thai carriers suspended their scheduled domestic operations in mid-July due to stricter lockdown rules imposed by the government. Bangkok Airways was the sole Thai airline to operate scheduled domestic flights in August. The carrier was able to capitalise on the "orange" (medium-risk) status of the Phuket and Surat Thani provinces and launched a 3x weekly service connecting Koh Samui and Phuket on August 25, 2021. It also continued to connect Koh Samui with Bangkok Suvarnabhumi throughout the month for essential travellers only. Since August 22, it has also been operating scheduled weekly flights between Koh Samui and Singapore Changi. It will restart four additional domestic routes from Bangkok Suvarnabhumi on September 1 and open the Bangkok-Koh Samui route for non-essential travellers.

Although the Thai government has relaxed some of the restrictions concerning travel, gastronomy, retail, and cultural events nationwide, 28 provinces (including Bangkok and all of its neighbouring suburbs) remain marked as "dark red" (highest risk) and a further 37 as "red" (high risk). Only 11 provinces remain "orange". Air travel is limited to a 75% load factor, and all passengers have to show proof of vaccination, a negative test, or proof of recovery from COVID-19.