The holiday group says this year is a record-breaker for bookings – which means more people than usual having to make last-minute cancellations.
The axed holidays can arise at any of the group's 23 holiday parks in Devon and Southern England, and are immediately "hot-tagged"
If they remain unsold after that time, they are marked back up to the full price and returned to Park Holiday UK's website.
There are no catches, says the company, but starting dates are often a week or less away, and customers have to choose from what's available rather than specify preferences.
But if they are prepared to be flexible, it says, the savings can be very substantial indeed.
For example a week's stay for six at Waterside Park in Paignton, Devon, was booked originally for £406.00 and re-sold as a cancellation for £129.00 - a 69 percent saving.
The company's cancellation desk opens for just two hours every day of the week between 12.00 noon and 2.00pm, and has a dedicated phone number: 0843 178 7090.
Park Holidays UK says that the quick-fire sales enable it to save a considerable amount in admin costs by just re-allocating the holiday rather than re-marketing it.
There is no element of a "mystery buy" about the holidays, says the group. Customers will know the exact specifications of each stay before they decide to buy.
The company suggests people calling the cancellation desk take a look at their website first and keep the page open during the call so that they can make a spot-check on the parks where cancelled deals are available