The NEXT time you’re bragging about your vacation on social media, you need to be careful what you post.

Experts have warned holidaymakers that sharing images of your boarding pass online could put you at risk of having your personal data hacked.

Although boarding passes may not contain your address or telephone number, they still contain many codes that could be used to find our information about you.

This includes frequent flyer numbers, your flight number and your name.

Some airlines have online systems to which it is possible to log in only with this basic data.

The barcode on the document could even reveal details such as passport numbers.

Privacy researcher Bill Fitzgerald said Conde Nast Traveler: “If you have a barcode on something […] you should definitely never post it on social media.

“If you’re worried about having your identity stolen, this is a really easy step to take, so you don’t share the barcodes in any way.”

Caleb Barlow, president and CEO of cybersecurity consultancy CynergisTek, told Forbes that to access a loyalty account, “all you need is your name, booking reference number and your loyalty number. These three things are on the boarding pass”.

He added: “There might be some basic password reset questions – but I might be able to get the answers to those just by looking on the web. And now that I have your frequent flyer account.

You should never throw it away either, in case someone gets hold of it – so it’s a good idea to shred it after your trip to protect your personal information.

You shouldn’t throw away your boarding pass for any other reason, as it could get you extra discounts on holidays, hotels, and airlines offering more cash with it.

Even mobile boarding passes can cause problems, due to third-party tracking leading to potential breaches.

The best option? Take a photo of your boarding pass and save it in your photos folder on your phone, Bill said.

There are also many boarding pass codes you need to know.

If you see SSSS on it, you might be late for your flight.

The code stands for “Secondary Security Screening Selection”, which means the passenger has been selected for further screening by security.

Anyone with this code is advised to show up an extra half hour early for the airport, as going through security will take significantly longer than usual.

And If you see GTE on your boarding pass, it may mean you don’t have a seat on a plane.

A traveler revealed how he received a boarding pass with GTE on it after he checked in at the airport rather than online – and had to find a seat on another flight instead.

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