Once you have booked and paid for your holiday, you can usually relax and eagerly look forward to the day you jet off knowing the hard work is done.
But holidaymakers could be faced with a surprise bill costing them hundreds of pounds extra if the value of sterling drops.
Extra charges
Package holiday firms are permitted to add an additional eight per cent on top of the original price of a holiday when their costs increase. This percentage applies even if a holiday has already been paid for, which could bring an unwelcome surprise to customers who have holidays booked.
Travel firms can add the charges up until 20 days prior to departure if their costs have gone up due to fluctuating exchange rates, higher fuel costs or tax changes.
The charges mean that customers who have paid £3,500 for a holiday could end up paying an extra £280 for their trip.
Falling value of sterling
While the additional charges may not be widely known, the rule has long been in place.
However, with much uncertainty surrounding the UK's departure from the EU, experts fear the extra charges may come into force due to the fluctuating rate of sterling.
自三年前全民公决以来，英镑的价值已经大大下降了。
2015年12月，它的价值约为1.40欧元，而现在在撰写本文时已下跌至1.10欧元。
Naomi浸出哪个？旅行现在敦促旅行社在预订之前清楚地告知客户，假期的价格可能会上涨。
Leach told The Sun, "A weakening pound will already be squeezing hard-earned holiday budgets, so millions of people who have already paid for a package deal could be in for a nasty surprise if travel companies use a little-known rule to charge potentially hundreds of pounds extra for their booking.
"The travel industry must make sure that this information is presented up front to holidaymakers when they book, rather than buried in the terms and conditions, so that they are fully aware of any additional charges they could face."
如果客户取消预订（照片：Shutterstock），仍然会面对通常的取消费
What customers need to know
Customers who don't wish to pay surcharges will still be faced with the usual cancellation fee if they decide to cancel their booking.
但是，如果公司收取的费用超过了这笔额外的金额，则客户有权免费取消罚款并获得全额退款。
Tour operators including Jet2Holidays, Lastminute, Loveholidays, Gower Tours and Wasteland Ski all reserve the right to change the price of your holiday after it has been booked and paid for, as stated in their terms and conditions.
However, Thomas Cook offers customers a so-called ‘Brexit price guarantee’, promising not to hike its prices "no matter what happens".
Guidance from the Association of British Travel Agents (ABTA) states that travel companies can increase the price of a holiday even after booking, providing it is included in their terms and conditions.
指导国家”,他们可以这样做,如果他们包括de this caveat in their booking conditions, but they can only increase the price to negate certain costs, for example changes in the price of transport resulting from the cost of fuel; changes in taxes or fees imposed by third parties; or changes to exchange rates.
“This is known as a surcharge and they have to follow strict rules to see if they can ask you to pay the surcharge.
"Unlike other travel companies, ABTA members won't pass on small price increases to you, as the Code of Conduct obliges them to absorb an amount equal to two per cent of your holiday cost."