Four million travellers who are planning a holiday or to do business in the United States of America this year are being warned about the unnecessary costs they could face if they don’t check their eligibility to enter the country. Those who ignore advice surrounding travel authorisation could be refused permission to travel – without any refunds for costs already paid.

The Electronic System for Travel Authorisation (ESTA), which assesses a person’s eligibility to enter the USA under the rules of its Visa Waiver Program (VWP), was introduced on a voluntary basis in August 2008 as a further layer of security measures implemented since the 11 September 2001 terror attacks. It became compulsory for non-visa-issued travellers from the UK, and other qualifying countries, in January 2009.

Although initially free, a charge was introduced in September 2010, causing hoards of people to rush to register in the summer of that year to beat the cost. As the ESTA lasts a maximum of two years, hundreds of thousands of people will now have ESTAs that are due to lapse, so must get a new one online before they intend to visit America.

Consumer Affairs Editor, Natasha-Rachel Smith from TopCashBack (www.topcashback.co.uk), is reminding those who applied for their ESTA two years ago, or those who don’t have one at all, to get a new ESTA if they plan to travel to the States. She says an early ESTA application prior to booking flights, accommodation and making other financial commitments can help save money and avoid the holiday becoming a disaster.

She said, “Being unprepared can be economically dangerous for those travelling this year as the associated costs can be high and in the worst cases, you could lose out on your holiday altogether. Many people can overlook simple procedures such as the ESTA, particularly those who haven’t travelled to America for several years and are unaware of its requirement. Airlines are instructed to refuse passengers boarding without valid ESTA, and you have no grounds for compensation.

“The US authorities are strict. Those who don’t have the right documentation, and it’s a particularly shady area for those with criminal records, won’t be allowed through. If you decide to go on holiday to the US, make applying for ESTA for the entire group of travellers top of the list, especially before booking flights, to ensure all are eligible to travel under the VWP. One refusal may mean applying in person at the US Embassy in London for a visa, which is very costly, time consuming and not guaranteed to be successful, or result in the group cancelling the trip altogether; which would be a financial devastation if non-refundable flights and accommodation have already been paid for.”

ESTA approval doesn’t guarantee entry into the US, but authorises travel to the country. It costs $14 (£9), which includes a $4 administration fee and a $10 acceptance charge. Rejection still costs the $4 administration fee. Applications can only be made online and paid with a credit card. However people are warned not to fall for copycat sites that charge more than $14 to process an application.