Starting from 12 January 2009, Singapore passport holders are REQUIRED by U.S. law to get hold of a travel authorization before travelling to the United States. This new ruling is applicable to all countries under the Visa Waiver Program (VWP) which includes Singapore.
Fortunately, this United States travel authorization can be applied and obtained for FREE online via the Electronic System for Travel Authorization (ESTA™) runs by the United States Department of Homeland Security (DHS).
The DHS cautions VWP travellers against using unauthorized 3rd-parties that charges a fee for the above and reiterated that
the United States Government does not charge a fee to obtain information about, apply for, or obtain a travel authorization through the ESTA™ Web site. Use of a private service to apply for travel authorization via ESTA™ will not expedite the granting of approval.
Visit the official ESTA™ website for your free United States travel authorization application.
More on Visa Waiver Program (VWP) for United States Travel
Singaporeans travelling under the VWP are not required to apply for and obtain a visa to enter the United States for trips not more than 90 days BUT are required to have a biometric (BioPass) or machine readable passports.
Your Singapore passport is machine-readable if it fulfills the following 3 criteria:
1) It is bar-coded on the bottom of the personal particulars page
2) It is issued after 2 January 1991
3) The particulars are not hand-written
In addition, if your passport was issued or renewed/extended on or after 26 October 2006, your passport is required to have an integrated chip with information from the data page;
or if your passport was renewed/extended between 26 October 2005 and 25 October 2006, your passport is required to have a digital photograph printed on the data page or an integrated chip with information from data page.
For more information and the latest updates, visit the Singapore Immigration and Checkpoints Authority website and the U.S. Department of State Visa Waiver Program page.