Holidaymakers who were hoping to head to France in the coming weeks are in some cases being told by accommodation providers that they will lose their money if they do not turn up.

Last weekend’s surprise decision by the UK government to require travellers returning from France to quarantine for 10 days – even those doubly vaccinated against Covid-19 – has left thousands of holiday plans in tatters, and many out of pocket as a result.

The move has left people, many of whom had bookings they had rolled over from 2020, having to cancel because they cannot afford to be off work for a further 10 days upon their return.

Related: UK’s restrictions on travellers from France excessive, says French minister

While DFDS, P&O and Eurotunnel are offering passengers the chance to defer their ferry or train bookings until September 2022, many gite and other accommodation providers appear to be declining similar requests.

In April 2020, the French government allowed holiday home and campsite owners to offer consumers an 18-month credit note, where its own Covid restrictions had halted tourism.

It was designed to save owners having to pay out large cancellation sums and to encourage guests to maintain bookings. A refund had still to be paid at the end of the 18-month credit note validity period if the credit had not been used.

However, if a replacement stay was offered for this year and agreed to, it appears the provider is free to apply the previous terms and conditions, meaning plenty of Britons will lose out if they cancel because of the change to quarantine rules at home.

Guardian Money readers have reported finding their deposits would not be rolled over for another year by their accommodation providers, as they were deemed to have cancelled.

Canvas Holidays told Emer Glynn in June it would not be rolling over her three camping bookings that were due to start on 24 July. However, it has since decided to allow customers to make free modifications up to seven days before arrival, allowing them to rebook until 2022.

Rory Boland, the editor of Which? Travel, says some package holiday customers may be able to claim a refund but those with flights and accommodation booked separately may face a battle.

“It may be more difficult to rearrange or secure a refund from your accommodation provider, as cancellation and rebooking terms can vary significantly. Those who are unable to defer their booking or claim a refund may have some luck claiming on their insurance – though policies that offer cover for needing to quarantine on your return are hard to come by.”

Ferry companies had been gearing up for their busiest six weeks of the year but say they were given one hour’s notice that France was being put on the amber-plus list on 16 July.

Travel insurance bought after March 2020 will generally not cover such cancellations.

This week, ferry firms were telling passengers to rebook or to accept a voucher for travel next year. DFDS, which runs the routes between Newhaven and Dieppe, and Dover and Dunkirk, said passengers had to call its dedicated helpline. Passengers booked on to P&O’s Calais route can apply online. Brittany Ferries and Eurotunnel were reporting long call waits from passengers, and were encouraging them to use their respective websites to cancel trips.