Entry Requirements
View information regarding entry requirements for the US, customs, and foreign consulates from the US Department of State.
International Dialing
To make an international call from the United States, dial access code 011, then your country code, then the phone number. The hotel operator can assist you. If you’re calling a number in the United States or Canada, direct dialing is: 1, the area code, and the phone number.
Tips for Traveling Abroad
Visit your local government websites for information about and recommendations for traveling to the United States. It is recommended that when traveling outside of your home country you register with your embassy or consulate by notifying that office of your travel dates and destination.
Visa Letter Requests
Your request will be processed within 10 business days. Requests for confirmation letters must be submitted by Wednesday, 25 February 2026. Requests for mailed letters will be reviewed, and additional fees will apply. The confirmation letter does not guarantee that you will receive a visa. Confirmation letters will include only the event title, dates, location, payment confirmation of registration fees, and that you are a presenter if applicable. If you are denied a visa, we will provide you with a full refund as long as we are notified before Wednesday, 25 February 2026. Attendees are advised to apply for visas as early as possible.
Submit a visa letter application »