Customers of some of the UK's biggest holiday companies will lose their money if told to self-isolate before a holiday.
Loveholidays and Travel Republic have told Which? that they can't guarantee customers will be able to either rebook or claim a refund if they're advised not to travel by a 'test and trace' or App.
Most travel insurance policies won't help either.
Expedia and On The Beach said they would do their best to help but didn't confirm whether they would allow rebookings. Another major company, Lastminute.com, did not reply to a request for comment.
Currently, the government is advising against all but essential travel. When this rule is relaxed, the NHS Test and Trace programme is regarded as vital in allowing the country to get back to normal. This means that if you've spent more than 15 minutes within two metres of somebody with COVID-19, you could be asked to self-isolate for 14 days. This could leave some holidaymakers completely out of pocket if they can't travel.
As self-isolation in these circumstances is voluntary, there is the risk that customers who have paid large amounts and can't rebook a trip might decide to travel anyway. This could potentially put fellow passengers or people at their destination at risk.
Irresponsible travellers could save themselves thousands by simply ignoring the requests of Test and Trace teams and going on holiday regardless.
Loveholidays told us: 'The Package Travel Regulations do not cover the situation where a customer in the UK is told to self isolate under the Test and Trace system.'
It said that it would depend whether the airlines, hotels or other parts of the holiday agreed to reschedule: 'In the circumstances that these suppliers do not offer free amendments for the customer, their normal cancellation terms will apply and the customer would be advised to check if they can recover these amounts from their travel insurance provider.'
Travel Republic also said that its customers needed to claim on their travel insurance because 'standard cancellation terms' would apply.
But the Association of British Insurer told us: 'Self-isolation may not be covered if there are COVID-19 exclusions in policies.'
Almost all travel insurance policies sold since lockdown began have had COVID-19 exclusions. Only in the last weeks has COVID-19 cover been available for the first time - from brands Cedar Tree, Cover For You and Outbacker, underwritten by AXA. They say they would cover customers who were told to self-isolate before a trip.
Independent holiday firm Trailfinders also said that it was not obliged to allow its customers to rebook. It told us: 'Travel principals have never been responsible for any financial loss for a traveller who is for any reason a no show. Cancellation conditions apply.'
However, it has introduced a new travel insurance policy that includes COVID-19. This provides 'cover for cancellation prior to travel (including quarantine if exposed to C-19), for curtailment of a trip, overseas medical expenses and extra accommodation costs, if required to quarantine by order of a treating doctor.'
Trailfinders travel insurance can be bought by customers of other companies as well.
Some travel companies have said that customers told to self-isolate this summer would be allowed to rebook for a later date.
BA Holidays, easyJet Holidays, Jet2 Holidays, Riviera Travel, Saga, Tui and Virgin Holidays all said that customers would be able to rebook for a later date.
Which? Recommended Provider Explore was the only firm we approached to say that its customers would also be able to get a full refund if advised to self-isolate. This applies to all its holidays except polar voyages.
Many airlines also now have schemes to allow passengers to rebook for later dates without paying a fee.
British Airways, Air France-KLM, easyJet, Emirates, Ryanair and Virgin Atlantic, among others, all allow you to move flights booked for this summer to a later date without penalty. Jet2 said it would let you rebook if you were asked to self-isolate.
The Department of Health and Social Care, which is responsible for the NHS Test and Trace service, warned that travellers could be asked to delay their return home if they've potentially been exposed to someone infected with COVID-19.
It also said that: 'British Nationals waiting to return home may be eligible for an emergency subsistence loan to cover essential living costs where they have exhausted all other options.'
If somebody on a plane is later discovered to have had COVID-19 those sitting within two metres will be asked to self-isolate for 14 days. However, flight crew and passengers sitting further away on the plane, will not.