More than a third (38%) of British holidaymakers travelling abroad this summer do not have travel insurance yet, a new study reveals.

As many as 8.6 million people could be putting themselves at risk of paying high medical or repatriation costs if they fall ill or hurt themselves abroad, and may even risk a delay in treatment, Abta warned.

Consumers are being urged to take out travel insurance as soon as they book their holiday and to ensure it covers any medical conditions or activities they plan to do.

Travellers are also being advised by Abta and the Foreign and Commonwealth Office to keep a copy of the policy number and insurer’s contact details with them at all times while they are away.

The new advice came as research found that more than one in five (21%) holidaymakers said they travelled without insurance in the last year. Of these, 37% said they didn’t think they needed travel insurance and more than a quarter (28%) said it was a risk they were willing to take.

Of those who have had to pay an additional cost on holiday due to being uninsured or not having the right cover, 34% have had to spend between £500 and £4,000.

Abta research also revealed that only a third of people who have bought travel insurance in the past 12 months kept their policy details on them at all times when away. But around one in ten have left the information with family or friends back home or given it to a travel companion – 13% and 9% respectively.

Having the travel insurance policy number and the international phone number for the travel insurance company to hand at all times, or with a friend or family member, will help those travelling access support as quickly as possible.

People are being reminded to ensure they take out cover as soon as they book their holiday to help protect them should they need to cancel due to an unexpected event or illness.

Abta chief executive Mark Tanzer said: “Millions of holidaymakers are heading off abroad each year either without the right travel insurance in place – or without any insurance at all. This leaves people at risk of having to pay significant medical costs or even facing delays in their treatment.

“Our message is clear – don’t take the risk, take out travel insurance and make sure it covers you for your circumstances and holiday plans.

“It’s also really important holidaymakers carry a copy of their insurance on them at all times, as well as leaving a copy with family or friends back home. That way they’ll be able to contact their insurer quickly and without hassle, should they need to.”

Julia Longbottom, FCO director of consular of services, added: “Most people enjoy trouble-free holidays overseas. However, I am concerned by these new figures showing that many British holidaymakers continue to travel without insurance.

“The risks are very clear. You could find yourself paying out thousands of pounds in medical bills if you don’t have insurance. It’s important to know the FCO cannot help fund medical bills if you or a family member are taken ill or hospitalised when abroad.

“Make sure you take out a travel insurance policy that meets your personal needs so you know you are covered should anything happen, and you can focus on having a relaxing holiday.”