Travellers from visa waiver countries must first obtain pre-approval from the Department of Homeland Security by following the instructions on the Electronic System for Travel Authorization website.1 The pre-approval application must be submitted directly online and takes 24 to 48 hours to process. Each approval is good for five years for multiple trips to the United States. Visa waiver passport holders cannot enter the United States without such an approval notice.
The visa waiver program is for citizens of certain countries who are visiting the United States for business or pleasure purposes for trips that last 90 days or less. For a complete list of countries currently participating in the Visa Waiver Program, please click here.2
Thus, if you have any employees who are planning to use the visa waiver program in the near future, they must apply for preapproval through the above-mentioned website before travelling to the United States.