Mark Warner Holidays orders its customers to pay currency exchange surcharge for pre-paid bookings

Mark Warner Holidays, which sells ski and sun package trips, emailed multiple customers last week to say it was exercising a little-known surcharge clause in its booking terms after the result of the June referendum on UK membership of the EU sent the value of the pound plummeting against the euro.

These customers have been slapped with a surcharge of between £30 and £50 per person, which is included in a revised invoice and payable within 14 days of that invoice being issued.

When contacted by MoneySavingExpert.com, Mark Warner Holidays refused to explain what will happen if customers decline or are unable to pay the surcharge.

However, its cancellation terms state that bookings cancelled less than 10 weeks before departure will be charged fees on a sliding scale. Those cancelling less than 14 days before departure will lose the entire value of their holiday.

Check out our Cheap Package Holidays guide for tips on how to book a bargain.

Customers threaten to boycott holiday firm over added surcharge

Mark Warner Holidays declined to comment when contacted by MSE, so we are unable to report how many customers have been asked to pay a surcharge.

Nevertheless, we've heard from at least one customer who received the updated invoice and found they'd been charged the maximum £50 per person, payable by Boxing Day. Others have left angry messages on Mark Warner's Facebook page deploring the surprise extra charge so close to Christmas.

One customer posted: "You have just lost a customer who is going on our 15th Mark Warner ski holiday. Never again. Hope it was worth it."

Another fumed: "I am disgusted with Mark Warner. We are going to cancel our holiday... Our holiday was booked three weeks ago – the pound has recovered since then. I wonder if they would refund us if the pound was healthier against the euro?"

The firm's move is in stark contrast to its behaviour on Black Friday, when it was offering customers 50% off children's bookings for certain types of holiday.

Some customers have been told they face a surcharge of £30 and £50 per person

Can Mark Warner do this?

We spoke to the Chartered Trading Standards Institute and it confirmed post-booking price variations are allowed under the Package Travel Directive, provided the following applies:

• The contract must state how this will be calculated – and should allow for up and down revisions.

• There are limited reasons why a price can be revised; these include variations in transport costs, fees and taxes, and exchange rates.

• Price increases cannot be made less than 30 days before departure.

• The package organiser must absorb the first 2% of any price variation.

Mark Warner has included terms in its contracts which allow a surcharge "in the event of changes in transportation costs... and/or in any dues, taxes or fees payable for services such as landing taxes or embarkation or disembarkation fees at ports or airports and/or where our costs increase or decrease as a result of any changes in the exchange rates which have been used to calculate the cost of your holiday".

It makes it clear it will absorb the first 2% of an increase as the directive stipulates, adding that: "If any surcharge is greater than 10% of the cost of your holiday (excluding any amendment charges), you will be entitled to cancel your booking and receive a full refund."

However, MSE understands that customers affected by this surcharge have been charged less than 8% of the value of their booking, meaning they are not entitled to a full refund if they cancel.

Could other package holiday providers follow suit?

Mark Warner appears to be the first travel company to surcharge customers because of the Brexit vote's impact on the pound.

We've asked Thomson/First Choice, Jet2 and Virgin Holidays whether they plan to surcharge customers, and whether the ability to do this is written into their contracts. We'll update this story when we know more.