Before heading off on their adventure holiday, travellers should purchase any foreign currency they need in cash, according to Which? Money.
Dan Moore, a senior researcher at the consumer watchdog, explained that many people think they get a "really good rate" when they purchase foreign funds using the internet.
However, he noted that there could be a range of hidden costs that travellers might not be aware of.
For example, some internet-based currency exchange companies will charge a fee for the delivery of the funds, while others will levy a handling bill.
Mr Moore recommended: "Get cash out of a hole in a wall in the UK, walk across the road to any of the exchange bureaus and pay in cash."
His comments follow the publication of data from FairFX earlier this month, which indicated that just four per cent of travellers understand that when the term "commission-free" is used, there could still be a cost associated with buying foreign currency.
