For travel on or after 12 January 2009, it will be mandatory for all individuals who plan to travel to the USA under the Visa Waiver Program to receive an authorisation through the ESTA website prior to travelling to the US.

Please ensure all passengers travelling to the US on or after the 12 January 09 have completed this authorisation. This authorisation can be obtained from the US Govt website...https://esta.cbp.dhs.gov/.