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BISO Home > IVO Homepage > Meeting Organizer Resources

MEETING ORGANIZER RESOURCES                                                                                                                      

If you are a conference organizer who anticipates high international participant attendance, you are encouraged to complete an online International Meeting Registration Form for your event. This data will be analyzed and used in ongoing efforts to increase scientific freedom.

- Since foreign attendees will need to apply for their visas at least three to four months in advance, meeting organizers are advised to send invitations letters to their attendees as early as possible.


We highly recommend that meeting organizers send participants an invitation letter to be submitted by the applicant when he or she applies for the visa.  It is also recommended that visa applicants have documentation that demonstrates the purpose of their trip. Letters that notify attendees that their paper has been accepted for presentation at the meeting may suffice, but sometimes a more personalized letter is needed.   

Sending an Invitation Letter
When sending a letter of invitation, be aware that signing such a letter imparts the imprimatur of the host organization -- whether it is a professional society or international union. Therefore, we recommend that the letter state only those things about the applicant that the person signing the letter can verify. If you decide that an invitation is appropriate, send it as early as possible and include the following specific information:

  • Name, dates, location and purpose of the meeting;
  • Name, date of birth, and passport number (if known) of the attendee;
  • Information on how transportation and local expenses are to be funded;
  • Information on the organization sponsoring the meeting and relationship to the attendee; and
  • Name, title, contact information (phone, fax, e-mail, meeting Web site) of person responsible for the meeting, in case the consular officer has further questions.

Visit the State Department Business Visa Center for more information.


U.S. visas are issued by American consular officials according to the requirements of the Immigration and Nationality Act. Some U.S. consulates receive hundreds of visa applications each week. Security checks and interviews are required for most visitor visas, resulting in a process that may take three months or more from the time of the visa application. Citizens of certain countries must have an invitation in hand before they can obtain a passport from their government and then apply for a U.S. entry visa.


Committed to encouraging international scientific exchange and collaboration, the International Visitors Office has been collecting data on the problems that individuals in the sciences are experiencing with visa applications. If your meeting participants experience difficulties in applying for a visa, they can report their case to us through the IVO Questionnaire. Please consult the questionnaire for details on eligibility.

For specific information on delays and denials, see the Travel to the United States section of this site.

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