Martin Lewis reveals huge holiday mistake that could ruin your trip

As we approach peak holiday season for Brits, Martin Lewis is warning holidaymakers not to make on crucial mistake that could cost you your trip.

There are several important documents to have in order when it comes to booking a holiday, most importantly your passport and your holiday insurance.

But, while many people wait until the date of their holiday to start their travel insurance, the money saving expert says this is a huge error.

For many years, Lewis has been urging people to buy their travel insurance as soon as they book their holiday for one very important reason.

"Every year, a few people contact me after something awful, such as a cancer diagnosis that needs chemo, but the airline or hotel won't refund them (they don't have to)," he said in his weekly money saving round up.

"I tell them, 'that's what insurance is for, speak to your insurer.'

Martin Lewis urges everyone to buy travel insurance at the time of booking (David M. Benett/Alan Chapman/Dave Benett/Getty Images)

"But if they haven't got it yet, no matter how horrid the circumstances, there's nothing that can be done. Don't be that person."

And it's true. Quality travel insurance has many benefits that go far beyond covering a trip to hospital while you're abroad.

Travel insurance protects against:

• Having to cancel your trip or return home early for reasons outside of your control
• Missing a flight or a travel delay beyond your control
• Belongings becoming lost, getting stolen, or getting damaged, including passports, money and baggage
• Personal injury, death and medical emergencies including hospital treatment and repatriation
• Accidental damage or injury caused by you

Holidaymakers need insurance to cover pre-holiday cancellations. (Oscar Wong via Getty Stock Images)

Citizens Advice warns that people without valid insurance will have to pay for any issues that arise out of your own pocket, while on holiday or you may not receive a refund for cancellations.

Meanwhile, Brits holidaying in Spain over the summer are being warned to make sure they have valid travel insurance or risk being refused entry to the country.

New laws imposed by Spain mean that tourists travelling from the UK must have comprehensive health cover as part of their insurance as part of the tourist hotspot's entry requirements.

If travellers are found attempting to enter Spain without the proper documentation, fines of up to €6,900 (£5,900) could be issued on the spot.

Anyone travelling to Spain in the next few months is being urged to check their insurance to ensure it meets the requirements.

(Hinterhaus Productions via Getty Stock Images)

"Not all policies will meet Spain’s new standards. While the Spanish government hasn’t specified exactly how much medical cover is now required, it’s recommended to have at least €30,000 for health-related incidents such as emergency medical treatment, hospital stays and repatriation. This figure is based on the typical minimum cover required for a Schengen visa," Michelle Cooper, director of travel insurance at Saga, said.

"It’s also now vital for travellers with pre-existing medical conditions to check their insurance covers these conditions, as this has been stipulated in Spain’s new rules.

"They equally say the policy must have a reasonable excess, which is somewhat subjective to each individual, but it could be considered between £50 and £250."