Expert explains why you should never print off your boarding pass before a flight

It can be very hard to resist a humble brag when we escape the British weather for a couple of weeks each year and head to more exotic shores.

An Instagram favourite is the pre-holiday snap of luggage, sunglasses, boarding pass and passport all lined up to perfection with a brag about your out of office and a few too many travel hashtags.

Most airlines tell us to arrive at the airport with our boarding passes in hand or face having to resort to asking the staff to print one off for us and paying the extortionate fee that comes with it.

However, a security expert has warned travellers never to carry a physical version of the pass and should instead opt to download the digital version stored on smart phones.

Always use an electronic version instead (Getty Images)

That's because your boarding pass that you use as a bookmark, leave on the plane or post on social media contains all the information hackers need to take over a frequent flyer account.

Frequent flyer points can be worth a lot of money online, with options to exchange them for a gift card or other products which can be sold on, and scammers are now trying to exploit it.

Caleb Barlow, president and CEO of CynergisTek, told Forbes : "All you need is your name, your booking reference number and your frequent flyer number. All three of those things are on the boarding pass.

"There could be a couple of basic password reset questions – but I might be able to get the answers to those just by looking on the web. And now I've got your frequent flyer account.

"If you print out a boarding pass and somebody picks it up, only one person is going to get your details. But when you put it on social media, you're talking about thousands of people who now have your details."

Years of accumulating points could be gone in an instant, with one website selling 100,000 airline miles for about £680 according to Forbes.

Cabel recommended those with a frequent flyer account set up a two-step authentication to ensure they keep a hold of the valuable points.

So maybe swap the photo of your flight documents for something really original, like the view of the clouds from the plane window.