Summer holidays have been given the go ahead this year under the UK Government’s new traffic light system.
People in England, Wales, Scotland and Northern Ireland are now able to jet away to green list countries.
But those returning from international destinations - even those deemed as low-risk - will need to take PCR Covid tests.
Under the plans, holidaymakers flying in from foreign places have to take tests at their own expense.
So, what is a PCR test and how can you get one for travel?
Here is everything you need to know.
What is a PCR test?
Polymerase chain reaction (PCR) tests are one of the main ways that people are being tested for Covid in the UK.
They are used to detect the genetic code of the virus - the RNA - by directly finding the presence of an antigen.
RNA is present in the body before antibodies can form.
By detecting viral RNA, PCR tests are able to signal whether or not someone is infected with coronavirus early on, even before symptoms start.
This type of test was introduced in the UK last year, with the hope of identifying people who are infected so they can isolate and prevent the virus from spreading to others.
PCR testing also allows public health officials to get a clear picture of the prevalence of Covid within a population.
You are able to book a PCR test if you are showing coronavirus symptoms, including: a high temperature, a new, continuous cough and a loss or change of taste or smell.
How does a PCR test work?
PCR tests are carried out using nasal and throat swab samples, and these are then sent to a lab.
They can detect very small amounts of RNA, meaning they are extremely sensitive and the best test to indicate current infection.
The test will confirm if someone has coronavirus, but what it doesn’t do is confirm whether they have had it and have now recovered.
Carrying out PCR testing can also be very labour intensive and time consuming as there are several stages.
Errors can occur between sampling and analysis, and false negative results are common - in fact, this can happen up to 30 per cent of the time with different PCR tests.
How do I get one for travel?
The number and type of test you need to get depends on the country you are visiting, with each destination having its own requirements for entry.
Most places now need you to have a negative Covid test taken usually within 72 hours before departure, and you will need to present your result before boarding the plane.
Many countries need it to be a PCR test, and some require it to be given by a professional instead of using a home testing kit.
You are not able to book a PCR test through the NHS for travel - they can only be taken privately from differing providers.
Then, rules for returning to the UK vary depending on whether the country you are coming back from is on the green, amber or red list.
Green list countries require one PCR test within two days of arriving back in the UK.
Amber countries need a pre-booked package of two PCR tests to be taken on days two and eight after you get back, as well as quarantining for 10 days at home. You can also opt to pay for another test on day five in England in order to end your self-isolation early.
Meanwhile, if you’re coming from a red list country you need a pre-booked mandatory 11-night quarantine hotel package which includes two PCR tests taken on day two and day eight of your return.
You need to use a testing facility on the government’s list of providers that meet the minimum requirements.
What is the difference between PCR and lateral flow tests?
Meanwhile, lateral flow tests are used to rapidly detect the presence or absence of Covid by applying a swab from the nose and throat to a special test kit.
They use a device similar to a pregnancy test.
The difference between this type of test and a PCR test is that results are provided without the need for full-scale lab analysis.
In this way, the results of lateral flow tests are delivered quickly - often within 30 minutes.
You do not need to have coronavirus symptoms to receive a rapid lateral flow test.
How much do PCR tests cost?
PCR tests for return to the UK from an international destination cost about £120 each, but prices are starting to come down.
Tour operators and airlines are partnering with labs to offer travellers cheaper tests, like Tui’s “green list” package which costs £20.
At-home kits are usually much cheaper than those administered professionally.