The mailbox of a well-known hotel in the heart of Lisbon was bombarded with queries as soon as Britain announced it was including the country on its travel "green list" this summer.
Manuel Pinto, Mundial Hotel director, is over the moon that British holidaymakers, who are essential to Portugal's tourism industry, will be able to return after a five-month travel ban, providing a much-needed boost to the struggling sector.
"I was delighted, not only on a personal level but for our country," Pinto said, standing in Mundial's rooftop bar, adding that British visitors had already booked around 4,000 room nights at the hotel this year.
Portugal was one of just 12 countries and territories to be added to Britain's "green list", allowing Britons to visit the country from May 17 without needing to quarantine, but still requiring two COVID-19 tests - one before returning to the UK and one on arrival into the UK.
Travel search website Skyscanner said there was a 616% increase in bookings to Portugal last week compared to the previous one, prompting airlines to add capacity to existing routes and, in some cases, launch news ones to meet demand.
Easyjet is adding more flights to Portugal for this summer, putting an extra 20,000 seats on routes including London Gatwick to Faro and Lisbon over the May-October period.
Still, a tourism sector scarred by Britain's last-minute changes to travel rules last summer and Christmas is braced for another turbulent year, and Portugal has yet to spell out exactly what rules would apply to Britons arriving.
Some executives said they were only too aware of how quickly the tide could turn again if coronavirus cases rose or governments changed their mind.
"I have to be cautious," Chitra Stern, CEO of luxury hotel chain Martinhal, said. "People are still booking refundable rates."
Other popular holiday destinations for Britons like Spain and Cyprus are on the "amber list", meaning travellers would need to quarantine for 10 days upon return and take two tests.
Tourism plays a crucial role in Portugal, representing around 15% of gross domestic product in 2019. But it suffered its worst year since the mid-1980s in 2020 as the coronavirus pandemic kept visitors away.
In 2020, only 460,000 Britons visited Portugal, from 2 million the previous year.
Eliderico Viegas, president of Algarve hotel association AHETA, said hotel owners were aware that they were benefiting from the fact that other countries faced greater restrictions.
"Our main competitors have been left out of the 'green list' for now,» he said. «It is a competitive advantage for us."
Britain's Thomas Cook said bookings had tripled compared to a week ago, with trips to Portugal accounting for a majority of that rise.
Airbnb bookings also started increasing and British airline easyJet said UK bookings for Portugal surged after the announcement, although it declined to put a figure on the rise.
Yet the high cost of COVID-19 testing and limited availability of flights pushing up prices, combined with the fact that the pandemic is still present, means the summer season is hard to forecast, even for Portugal.
"It's not just a matter of a recovery of traditional flying, it's a complete reshaping,» travel consultant for Bain & Co, Geoffrey Weston, said. "That's why this is so hard to judge."