Overseas tourists poured into Bangkok and the holiday island of Phuket on Monday as Thailand kickstarted its tourism industry after 18 months of Covid curbs.

The coronavirus pandemic hammered the kingdom's tourism-reliant economy, which last year saw its worst performance since the 1997 Asian financial crisis as arrivals dwindled more than 80 percent.

Thai authorities have given the green light to vaccinated tourists from over 60 "low-risk" countries to skip hotel quarantine -- providing the sector with a much-needed lifeline.

Bangkok's Suvarnabhumi airport and Phuket's international terminal were the first on Monday morning to receive visitors, with mostly European tourists greeted by staff dressed in personal protective equipment to process their documents.

"The paperwork was a big effort and a struggle, but it feels good again to travel and get back to normal life," said German tourist Marcel Florian Popp, 25, after he and his friends passed immigration in Bangkok.

In Phuket, Lin Turley, 68, said he and his wife were regular visitors to Thailand before the pandemic and were looking forward to a relaxing month of golf and swimming in the island's clear turquoise waters.

"We have just come out of a cold Europe so we are looking forward to some warmth," he told AFP.

"We want to relax and enjoy being back in the Land of Smiles."

Visitors are required to take a Covid test upon landing and spend a night at a government-approved hotel to await the results before being allowed to travel freely across the kingdom.

By late afternoon, about 1,500 foreigners had landed in Suvarnabhumi airport, said director Kittipong Kittikachorn, adding that he expects half of November's estimated 135,400 visitors to be foreign.