USA border crossing data

If leaving the United States on an airplane or vessel owned by a commercial carrier, the departure from the United States has been recorded in a database and is available to the Border Patrol. However, it is best to keep proof (e.g., boarding pass) just in case to facilitate future entry into the United States.

If you leave the United States by land, private vessel, or private airplane, you must notify the Border Patrol of your departure from the United States yourself.

If timely departure from the U.S. is not recorded or you cannot prove it, if you attempt to re-enter the U.S., the Border Patrol may assume that you were in the U.S. beyond the authorized period of stay, in which case your visa may be invalidated and you may be denied entry into the country.

Citizens of countries covered by the Visa Waiver Program (VWP) who remain in the United States beyond the authorized period of stay will be required to obtain a visa from a U.S. consulate before re-entering the United States.

To notify the U.S. of your departure you must complete Form I-94w, and provide proof of departure from the United States.

This can be:

the original boarding pass for a return flight from another country (e.g., Canada) if the flight departed from there to your home country.
copies of the border crossing stamp in your passport showing entry into other countries after leaving the U.S. (attach copies of all pages of your passport, including personal information and photo pages, except blank pages), and as copies of additional documents such as:
dated earnings statements or vouchers issued by your employer verifying that you have worked abroad since returning from the U.S,
Dated bank statements showing a transaction indicating that you stayed in another country after leaving the United States,
school transcripts showing that you started school abroad after returning from the U.S., and

proof of purchases made abroad after returning from the U.S. in the form of a recorded and dated confirmation of payment transactions made by credit card. The credit card number must be concealed.
To help the Border Patrol understand the situation and promptly make the necessary corrections to the records, attach a written explanation in English. Your declaration will not be accepted without the documents mentioned above. If possible, send original documents or legible copies. If you send originals, keep copies. Original documents will not be returned.

It is recommended that you keep copies of the documents you send and bring them with you when you return to the U.S. to show them to an immigration officer in case of doubt when crossing the border. Having the aforementioned documents will also allow you to record your previous departure if you have not already corrected the data in the database.

Individuals who make short trips (30 days or less) to Canada, Mexico, or the Caribbean Islands while in the United States should retain Form I-94 or I-94(W). The form should be returned only upon returning home from the United States.

Delays beyond the traveler’s control, such as flight cancellation or delay, a medical condition requiring medical attention, are not considered an extension of stay without authorization, but documentation explaining the situation must be provided when traveling to the United States again. If the flight is delayed, you should request a written statement from the airline confirming the situation or a copy of the canceled boarding pass.

Documents should be sent to:

Coleman Data Solutions
Box 7965
Akron, OH 44306
Attn: NIDPS (I-94)
USA
(if you are using the U.S. Postal Service)

OR

Coleman Data Solutions
3043 Sanitarium Road, Suite 2
Akron, OH 44312
Attn: NIDPS (I-94)
(if using FedEx or UPS)