What you need to know about traveling to Europe this summer

(CNN) — In non-pandemic summers, both continental Europe and the United Kingdom draw crowds of tourists from around the world. Last summer, they couldn’t get there. This summer many should be able to, though the tangle of entry requirements will vary by country and could change quickly.

Here’s a guide to help you determine where and when you can vacation this summer in the 27 member countries of the European Union and in non-EU European countries.

When will I be able to go?

This will vary by country visited and the traveler’s home country. Throughout Europe and the United Kingdom, conditions of and requirements for entry differ from country to country, as does timing. The EU is trying to create more universal requirements for tourism, but each country retains sovereign powers to controls its borders in an emergency.

On May 20, the EU also adopted a “roadmap,” or recommendation that would allow vaccinated travelers from outside the EU to go to Europe; details are expected to be finalized by the end of June. The roadmap will give each country an “emergency brake” mechanism that would close borders if there were a new Covid-19 outbreak, either in the traveler’s destination or home country.

While EU-wide policies are still being finalized, a number of European countries have opened or will shortly open their borders to non-European travelers under certain conditions; these include Greece, France, Italy, Spain, Turkey and Iceland.

Meanwhile, England, Northern Ireland, Scotland and Wales — the four countries of the United Kingdom, which is no longer part of the EU — have each established its own criteria for tourist travel, reviewed every three weeks. These criteria involve a red, amber and green system that could entail a quarantine and various tests, depending on the traveler’s home country.

What proof will be required to show I’ve been fully and properly vaccinated?

In May the EU adopted the concept of an “EU Digital Covid Certificate” for its own citizens, proposing that it be in place by July 1. This would digitally prove that the certificate holder had been fully vaccinated with an EU-approved vaccine (AstraZeneca, Johnson & Johnson, Moderna or Pfizer), had recovered from Covid-19, or had tested negative for it.

Although it is hoped Americans will eventually be able to digitally provide the same information when they travel to Europe, in order to gain entry there, it is unclear when and how this will happen, in part because the US government has not established a similar digital system. Currently, it appears Americans may be able to provide alternative types of proof, such as their paper vaccination card, for EU travel.

Will I need a Covid-19 test?

A Covid-19 test requirement will depend entirely on where you’re going. For example, as of now, England requires some visitors to test both before and after arrival. Italy now lets passengers on special “Covid-tested flights” from the US, Canada, Japan and the United Arab Emirates visit; passengers on these flights must test for Covid-19 before departure and on arrival in Italy, as well as on departure from Italy.

Anyone age 2 and older flying back into the United States will need a test within three days of their flight’s departure or prove they’ve recovered from Covid-19.

Can I book now, before the rules are finalized?

You certainly can, though thoroughly research cancellation and refund policies of any airline, hotel, tour operator or attraction you are considering before you book, in case anything changes — in your health or in the pandemic situation in your country or the country you are visiting — that would prompt you to cancel your trip.

Jennifer Tombaugh, president of Tauck, a Connecticut-based tour operator that specializes in travel to Europe, says travelers can “absolutely book now, though they should make sure they have a very good understanding of cancellation fees and any other restrictions. The bottom line is that it’s very important that you read the fine print, understand what payment is required when, what is refundable and what is not. A knowledgeable, plugged-in tour operator or travel agent can help you with this.”

How quickly will destinations get booked up, once any new rules are announced?

This will depend on the destination and if it is already accepting tourists, for example, from other European countries, the United States or Asia.

Greece, which has been letting certain tourists in since mid-April, is a popular destination that will probably get booked quickly. So is Portugal, which ended a ban on British tourists earlier this month (May).

It will probably be easier to book a vacation in a major European or British city, where many hotel rooms will likely be available, than in a small resort town with limited lodging options.

How difficult will it be to book a reasonably priced flight to Europe?

Terry Dale, president and chief executive of the United States Tour Operators Association, suggests “booking now — if you’re serious, get a placeholder.”

Both he and Eduardo Santander, executive director and chief executive of the European Travel Commission, a nonprofit organization that represents European national tourist offices, expect there might be a shortage of capacity on flights to Europe, since travel there has been in such flux, and it is not easy for carriers to respond quickly to increases in demand.

However, Craig Jenks, an expert on the transatlantic airline market, believes if you “book closer in, there will be opportunities” somewhere, due to imbalances between demand and supply. He suggests monitoring flights on websites like Google, Expedia and Travelocity.

Will I be able to cancel, if there’s a renewed shutdown or other unforeseen event?

That will depend entirely on the travel supplier — such as an airline, hotel or tour operator — you’ve booked. Although most airlines have been very flexible about not enforcing cancellation or rebooking fees during the pandemic and some have even eliminated certain change fees, it’s not clear how long their flexibility will last, if air travel demand continues to strengthen.

Travel agents encourage the purchase of trip insurance: Some policies are now available that provide coverage for pandemic-related disruptions, such as Covid-related cancellation, Covid medical coverage, and additional accommodation or transportation.

Will I be able to visit more than one country in Europe, whether I am traveling by land or on some sort of cruise ship?

This situation is in flux, as vaccine programs are rolled out, allowing borders to open, and as new variants are discovered, which close borders down. When the EU reaches agreement on standards for reopening and employs the Digital Covid Certificate, intra-European travel should be relatively easy and possible.

But, as of now, for example, Americans can go to Greece without quarantining, but they cannot visit Germany or the Netherlands. If you are working with a tour operator or a cruise line, it will have the latest information on intra-European travel.

Will I have to be tested or quarantine when I return to my home country?

What are the best sources of information to help me plan my trip?

Tom Jenkins, chief executive of ETOA, the trade association for European tour operators, believes major European cities have been pummeled by the pandemic and therefore will be evolving. “The service economy of Europe is adapting to huge changes in demand. Yet now is a great time to go there. Michelangelo’s ‘David’ and da Vinci’s ‘Mona Lisa’ didn’t catch Covid and they are feeling very lonely.”

“It will be an exciting and wild time,” predicts Tombaugh. “Expect the unexpected and have a good sense of humor to make the most of the new world of travel we are all discovering.”

Top photo: Balos beach and its lagoon on the island of Crete on May 13, 2021. Photo by Louisa Gouliamaki/AFP via Getty Images