How do I know if I need a visa to travel to the United States to attend Plant Biology 2024?

Please use the U.S. Department of State Visa Wizard to determine if you will need a visa.

I need a visa. What do I do?

This can be a lengthy process. PLEASE BEGIN NOW.

For current requirements specific to your situation, please check with your local U.S. consulate or embassy or the U.S. Department of State visa information website.

You may be required to schedule a visa interview, and wait times for interviews can be significant. See the home page of the U.S. Department of State visa information website for estimated wait times. APPLY EARLY, as soon as you decide to travel to Plant Biology 2024 and no later than March 1, 2024.

What is the Visa Waiver Program, and how do I know if it applies to me?

If you are a citizen or a national of a designated country, the U.S. Visa Wizard may indicate you are eligible for the Visa Waiver Program.

If you qualify under the Visa Waiver Program and do not need a visa in your passport, you must still have valid Electronic System for Travel Authorization (ESTA) approval and meet all the requirements listed for the Visa Waiver Program.

Our most important advice is to APPLY EARLY FOR ANY SERVICE. Apply as soon as you decide to travel to Plant Biology 2024 and no later than March 1, 2024.

The best resources for advice specific to your situation are your local U.S. consulate or embassy and the U.S. Department of State visa information website.

How do I obtain a Letter of Invitation?

A request for a letter of invitation can be made only after you register and pay for Plant Biology 2024.

All requests must be emailed to Please provide:

  • Your full name
  • Your mailing address
  • The name of your institution
  • Your passport number and date of issue
  • The country that issued your passport

If you are affiliated with a society (e.g., ASPB, Canadian Society of Plant Biologists, Taiwan Society of Plant Biologists, Chinese Society for Plant Biology, etc.), please indicate which one.

Please allow up to 72 hours to process your request and prepare a letter of invitation. The letter will be returned by email. According to the U.S. State Department, an electronic letter should be acceptable for visa purposes. Should the U.S. Embassy to which you are submitting the visa request insist on a hard copy, we can mail you a letter of invitation. As the visa application process can be lengthy, please register and start this process early.

What do I need to enter the United States?

All international visitors must present a passport or secure document when entering the United States. Most travelers to the United States must hold a valid visa and a passport that is valid six months longer than the intended visit.

If you have questions not addressed here, please email Allow 72 hours for a response.