Those hoping to snap up a cheap last-minute break this summer need to watch out for potential holiday scams.

As one of the busiest booking periods for last-minute summer getaways begins, experts at GetSafeOnline.org and travel association ABTA warn that bargain hunters are ignoring basic online fraud-prevention measures in their rush for the ultimate holiday bargain, increasing the risk of being caught out by bogus breaks.

In the worst cases, holiday makers could be handing over their hard-earned cash for 'dream holidays' that don't exist.

Almost 1 in 3 web users booking holidays online don't confirm the authenticity of travel providers (e.g. by checking they are a member of a recognised trade association) before handing over payment details - one of a few basic, but important, lines of defence against fraud.

Other common pitfalls include not checking the web page is secure when entering payment details to help ensure credit card information cannot be intercepted by fraudsters - over 1 in 5 holidaymakers neglect to do this.

Such measures become even more critical when consumers begin hunting for 'almost too good to be true' deals via the web, leading many to opt for unknown or unrecommended providers.

Tony Neate, managing director of GetSafeOnline.org, says: "When we've been working hard the rest of the year, for most people making sure we have a great summer holiday is really important. Fraudsters recognise this and play on people's desires - we get caught up in the excitement of a 'bargain dream holiday' and cautiousness goes out of the window.

"When things don't start to add up, that's when you really need to do your research. For example, if you decide to rent a villa or holiday home from an individual and they don't provide a contact telephone number or don't respond to calls, and they ask for full payment upfront to be made by a cheque in the post or wire transfer, then you need to be very careful. For private rentals, this may be the only way they can take payment, but it does make them almost impossible to track."

Two-thirds of people even say they've never heard of holiday rental scams, 68% are not aware of bogus holiday sites, and 81% unfamiliar with 'gap-year' fraud.

And over 1 in 5 have been approached with holiday deals or villa rentals via unsolicited emails, phones calls or SMS text messages from individuals or organisations they don't know - another area where you need to be extremely cautious.

Mike Monk, head of financial services at ABTA, says: "By being aware of the risks, knowing the 'tell-tale' signs to look out for and taking some basic prevention measures, there's no reason why holidaymakers cannot enjoy the benefits of booking online."

Here are some tips.

• Too good to be true? - five-star holidays at two-star prices probably are. If something doesn't seem right, take additional steps to verify the offer and if still in doubt, stay away.

• Don't fall for fake competition scams - similarly, a common trick by fraudsters is an email claiming you have won part of a luxury holiday, but need to pay a small fee to secure it.

• Check for approval - find out if your holiday provider is a member of ABTA or comparable travel organisation. If not, particularly in the case of private rental, do an online search to see if other travellers have had a bad experiences.

• Check authenticity of private villa rentals - speak to the owner/agent directly via telephone; if the number isn't provided email and request it. Although some owners will be unwilling to disclose these on their websites, there should be no problems getting these at the booking contract stage when the owner knows you are serious and the owner is genuine.

• Do your research - get the full address and find it on Google maps, and ask for a full contract which should set out all the terms and conditions of the rental, deposits, payment terms etc.

• Choose the right travel insurance