UK holidaymakers are being put on alert over a crucial mobile phone regulation at airports, with the Foreign Office cautioning that non-compliance could mean your gadgets get left behind.

Jet-setters departing from UK airports this year must adhere to a vital rule concerning their mobile phones, tablets, and laptops, or face the possibility of having to abandon them on-the-spot.

Hand luggage restrictions differ among airlines, with Ryanair, Jet2, TUI, and easyJet each having their own list of banned items. Passengers are generally prohibited from carrying weapons, flammable substances, e-cigarettes, and certain battery types in their checked luggage.

A not-so-well-known stipulation regarding electronic devices exists, and if violated, travellers will be barred from bringing them onboard. Passengers may be asked to demonstrate that their device can be powered on.

Should a device be inoperable or uncharged, rendering the passenger unable to switch it on upon request, it may be denied boarding. The British Foreign Office advises: “Make sure your electronic devices are charged before you travel. If your device does not switch on when requested, you will not be allowed to take it onto the aircraft.”

Although it’s unlikely every passenger will need to verify their device’s functionality, random checks can occur at security points within the airport – and nearly everyone now travels with a smart device.

Despite this policy being well-established in the UK, numerous travellers remain oblivious to its existence, reports Birmingham Live. Britons heading off on their summer holidays this year are being urged by travel insurance experts to take note of strict rules in place.

Rules vary from airline to airline, so travellers should check before their flights. British Airways, for example, states: “You can generally take electric and electronic items in your hand or checked baggage, but you need to follow specific safety instructions.

“Airport security staff may ask you to turn on electronic or battery-powered devices, such as phones, tablets, e-books and laptops, to demonstrate they function. If you’re not able to do this, you will not be able to take your device with you.”

The airline also adds: “Please ensure that any items in your hand baggage are fully charged and switched on before you arrive at the airport. If your device is not charged, please place it in your checked baggage. If you are connecting, make sure that you do not deplete power in your devices during the first part of your journey as charging points at airports might be very limited and you may need an adapter.”

EasyJet also states in its guidelines: “You also need to make sure that your device stays charged if it runs out of battery and you can’t turn it on to scan your boarding pass as required, easyJet cannot accept responsibility if you are as a result not able to fly.”