If you are planning to attend this conference from outside the U.S, you’ll first need to determine whether you need a visa.


If you are unsure whether you need to obtain a visa or ESTA, use the U.S. Department of State’s Visa Wizard to find out which you should apply for.

Do I need a visa or ESTA?

Once you’ve determined which visitor category is most appropriate for your travel to the United States, please review the appropriate section below.


If you have determined that you do need a visa, you will need to apply for the right kind of visitor visa - usually a B1*, to attend a scientific, educational, professional, or business convention or conference for a business visit - and follow the instructions provided by the State Department.
*Please check current visa categories and requirements, as these could change.

The U.S. Department of State now requires you to appear for a personal interview in order to apply for a visa and requires that you have a machine-readable passport. Some consulates have up to a four-month waiting period for an interview, so please contact your nearest consulate as soon as possible to request an interview date. If you have difficulty getting a timely interview appointment, please contact our International Department at and we will do what we can to help.

ASCE cannot refund registration fees after the registration cut-off date (to be announced) due to an individual's inability to obtain a visa, so please file your paperwork as far in advance as possible in order to be eligible for a refund prior to the registration cut-off date.

ASCE cannot intervene on behalf of the invitees with the Embassy or U.S. Consulate via fax, phone, surface mail, or email. The U.S. Department of State provides information on traveling to the United States regarding passports, international travel, etc.

To request a Letter of Invitation to attend the Conference, fill in this online form. Registration must be completed and paid before a Letter of Invitation can be sent. A copy of your registration confirmation email must accompany your letter request. Please be ready to provide your complete official name, date of birth, physical address, email address, and passport number (if available).

The Letter of Invitation will ONLY be sent via email to the email address that you provide. The Letter of Invitation cannot be emailed or sent to the Embassy or U.S. Consulate.


Effective January 20, 2010, inbound travelers to the United States from Visa Waiver Program (VWP) countries may be denied boarding by the airlines if they haven't complied with the U.S. Department of Homeland Security's Electronic System for Travel Authorization (ESTA) program. U.S. Customs and Border Protection [CBP] will handle emergencies on a case-by-case basis. ESTA requires all international travelers from VWP countries to register in an online database. Previously, international travelers had to fill out an I-94W form before each trip, but ESTA seeks to streamline and update the process.

Now, international travelers from VWP countries to the United States must go to the ESTA website and fill out an application before entering the U.S.A. by air or sea. If approved, the authorization is good for two years and can be renewed. Travelers no longer have to fill out an I-94W form before each trip. U.S. officials say ESTA will speed up the process for travelers, enable customs officials to screen passengers in advance, and improve security. The ESTA requirement does not affect U.S. citizens returning from overseas, people from VWP countries traveling on a valid U.S. Visa, or travelers from non-VWP nations.