The gradual reversal of Covid restrictions on international travel has provided a welcome fillip for tourists but left many of the world's would-be travellers confused.
The UK is a significant contributor to the confusion.
Portugal which was the only major country placed on the green list initially. But only a couple of weeks later, the government suddenly reversed the decision because of rising case numbers of the Indian variant in the popular Iberian destination.
Portugal's demotion to the amber list infuriated the travel sector. London's Heathrow Airport said the sudden removal risked sending a message that the UK "remains isolated from the rest of the world".
Germany is on the UK's amber list but on Saturday it imposed fresh restrictions on UK travellers because of concerns over the spread of the Indian variant, of which Britain has the most cases in Europe.
With the EU moving ahead with plans for free travel within the bloc for those who have been vaccinated, the scope for confusion widens.
While the EU has a plan for a unified reopening, some member states have moved ahead more quickly. And for each international trip, there are rules for entry into the destination country and separate regulations for leaving and returning home.
Here’s a rundown of current rules for high-demand European and transatlantic travel. Most Asian countries, along with Australia and New Zealand, are mostly closed to outsiders.
International travel rules by country
The traffic-light system for travel is explained here.
Many green list destinations aren't letting people from Britain in, but the list still looks set to expand. Ryanair chief executive Michael O'Leary predicted Italy and Greece will be added by the end of the month, followed by Spain in June.
There are also intra-UK restrictions, with Scotland banning travel to parts of England where the Indian variant is on the rise.
Travellers who have been through a red list country over the past 10 days are barred from entry unless they are British or Irish nationals or UK residents.
Germany provides more visitors to Europe’s beaches than any other nation. It loosened border curbs with member countries of the EU and the Schengen free-travel zone on May 13, giving its citizens access to more destinations than their British counterparts.
Fully vaccinated or recovered people no longer need a negative Covid-19 test and don't have to quarantine when they re-enter the country from those locations, removing a hurdle for Germans considering a holiday on the continent.
Those who don’t meet those criteria will, for now, have to quarantine from designated risk zones, including all of Italy and Greece, as well as swathes of Spain.
Meanwhile, travel from so-called third countries like the post-Brexit UK remains severely restricted.
People can only enter if they're residents of Germany, have an important role or if there is an urgent need to travel, such as life-or-death medical care.
Citizens from Australia, Israel, New Zealand, Singapore and Thailand can enter Europe’s biggest economy without restrictions. China, Hong Kong and Macau residents will also be allowed when Germans are granted equivalent entry rights, according to the interior ministry.
The epicentre of the first coronavirus wave in Europe has relaxed rules for tourists entering from abroad.
Arrivals from most EU countries, Switzerland, the UK and Israel can avoid a 10-day quarantine with a certificate showing a negative coronavirus test no more than 48 hours before landing. Entry from San Marino and the Vatican City, microstates nestled within the Italian peninsula, is unrestricted.
Travellers from Japan, Canada and the US face restrictions on movement and must isolate for 10 days.
Most other tourists aren’t allowed to enter, although Americans can get around the quarantine if they join certain Alitalia SpA, Delta Air Lines and American Airlines Group flights between Rome and Milan on one end and New York’s John F. Kennedy International and Atlanta on the other, with Dallas Fort Worth potentially being added.
France allows entry from the EU and a handful of other countries so long as people complete a form and receive a negative test within 72 hours before travel. Arrivals from seven nations, including the UK, New Zealand and Japan, must also self-isolate for a week.
Passengers from higher-risk countries, including Argentina, India and South Africa, must have a valid reason for travel and may be required to take a second test depending on the timing of the pre-flight screening. A 10-day quarantine is mandatory.
A metropolitan curfew is still in place in France from 9pm through 6am. Residents are not allowed to travel outside of the EU or seven designated countries unless they meet a list of exemptions.
Spain and Greece
Tourists from Olympics host Japan and the UK can enter Spain from Monday without a PCR test.
This should give a major boost to the country’s tourism sector since Britain provides its biggest source of visitors – but there’s a hitch.
With Spain on the UK's amber list, Britons will have to self-isolate once they get home. And there’s testing required on departure as well as return, which will quell some of the enthusiasm.
Some EU and European Economic Area arrivals can go to Spain without a test, along with people from Australia, China and Hong Kong – places that are also mostly shut off.
Arrivals from the bulk of EU countries, including Germany, Ireland and France, must take a test. The list is reviewed every two weeks.
Those entering Spain from India must quarantine for 10 days, a period that can be shortened with a negative test on the seventh day.
Entry to Spain will get easier from June 7, when those vaccinated with EU or WHO-approved shots will be welcomed and can travel around the country freely.
For Greece, travellers from the EU and Schengen Area can enter without self-isolating as long as they can prove they’ve taken a negative PCR test within 72 hours of arrival. The test isn’t required for those who have completed their vaccinations, or recovered in the past nine months, and can show proof.
Other countries that are allowed to enter Greece under the same conditions include the US, the UK, Russia and Canada.
Airlines rushed capacity into Portugal after the UK put it on its green list in May. Their plans were upended when the government reversed the decision just a couple of weeks later in early June. demoting the Iberian country to amber.
Tourists from the UK, and EU and Schengen Area countries can go as long as they present proof of a negative test carried out 72 hours or less before the flight.
People from countries with high Covid-19 incidence rates of 500 cases or more per 100,000 inhabitants over the past two weeks can only make essential trips and must quarantine for 14 days at home or at a location chosen by the health authority.
The list includes South Africa, Brazil, India, Cyprus, Croatia, Lithuania, the Netherlands and Sweden, although it doesn’t include people who have made airport stopovers in those places.
Trans-Atlantic travel has begun to open up, but so far it's very much a one-way street with Americans able to fly to some European countries but with no reciprocal arrangements in place.
Under a presidential decree issued by Joe Biden, entry to the US is denied to anyone who in the previous 14 days has been in the UK or Schengen Area, which includes 22 EU members, plus a number of other countries like Norway, Iceland and Switzerland.
There’s an exception for US citizens, permanent residents and their families, so Americans can return home with ease if they can get to the destination country.
To enter the UK, amber-listed arrivals from the US must self-isolate for 10 days. There's some expectation that the US may soon be added to the green list, with momentum building toward a bilateral accord in the run-up to the G7 meeting in England next month.
Americans can travel to parts of continental Europe without the need to isolate, generally on the same basis as visitors from within the region.
Those parts include Greece and certain flights to Italy, as well as Iceland and Cyprus. France will join the list on June 9 while strong restrictions still apply to Germany, Portugal, the Netherlands and Ireland.
The EU's move to work toward a more comprehensive reopening for vaccinated visitors will favour Americans and other countries where vaccination rates are high. With the UAE currently topping this chart, it bodes well for Emiratis.
The unvaccinated could potentially get in too, if the US is added to an EU "white list" that currently features eight countries, including New Zealand and Israel, with low Covid-19 rates.
Getting added isn’t certain, however, and Bloomberg reported last week that talks had stalled.