The UK government on Friday issued new rules for transport operators after border officers raised fears some airlines were not checking whether passengers had tested negative for coronavirus before boarding. Transport operators are now required to warn passengers that they are supposed to show a negative Covid test at four points – the booking stage, at check-in, between 24 and 48 hours before departure and on the boat, plane or train. The government said the warning “must be displayed prominently and not incorporated among terms and conditions”. The ISU, a union representing border and customs officers, had complained that some airlines were letting passengers board without negative test results. The test is supposed to be taken 72 hours before departure. Failure to present a test on arrival in the UK could result in a £500 ($683) fine for individuals. Airlines can also be fined £2,000 per passenger if they let them on the plane without the correct certificate. About 30 passengers were fined on the first day of the new requirement, the Home Office said. The Civil Aviation Authority is responsible for taking action against airlines but the Department for Transport did not say whether any fines had been issued. Lucy Moreton of the ISU said some airlines were failing to comply with the rules. "Some people aren't getting the test, I can't speculate as to why … (but it) puts everybody at risk," she told <em>The National</em>. Test results must be presented in English, Spanish or French, and include information about the type of test carried out and by whom, according to guidelines. The new requirement has led to lengthy delays at the border as officials complete the triple check of passports, the negative test result and the passenger locator form, used to enforce the mandatory 10-day quarantine. <em>The National </em>contacted several major airlines to determine what action was taken against passengers who did not present a negative test at check in. American Airlines said such passengers “will not be allowed to board their flight bound for the UK”. EasyJet said: “We aren’t seeing instances where passengers are failing to present a negative Covid test, however, failure to do so would mean they are unable to fly with us.” Ireland-based RyanAir, however, called for more information on whether some travellers were exempt from the rules. “If you begin your journey from Ireland, Northern Ireland or Scotland you may not need a test,” a spokeswoman said. “We await further clarity from the UK government and we will provide the latest information once it becomes available.” Communication of the new requirements is also causing confusion. Dr Roberto Di Febo, who was departing Rome for London on Thursday, was prevented from boarding his flight because his negative test result was in Italian. The doctor, who works in the UK capital, said at least five other passengers were prevented from boarding the flight. "I passed the checks and I was already at the gate when they told me I would stay on the ground," he told newspaper <em>la Repubblica</em>. The Department for Transport said: "If passengers are stopped by UK Border Force without evidence of a negative test, this information will be passed onto the Civil Aviation Authority to consider what action is appropriate to take, including potential fines for airlines."