To fill out Form 8840, you must have a legal U.S. visa and the knowledge to properly establish a closer connection to a foreign country. You must also know your passport number, income and how many days you spent in the United States, explains the Internal Revenue Service.
To prove foreign residency, the IRS must establish that you have more significant contacts in a foreign country than in the United States. Some evidence needed to prove this includes the country of residence designated on important documents, past filed forms and the location of your family, permanent home and personal belongings, according to the IRS.
Part one of Form 8840 requires you to enter information about your U.S. visa, the name of the country where you are trying to prove residency and information on your passport, such as where it was issued and how many days you spent in the United States. This is intended to establish your connection to the foreign country. Part two is where you officially state the name of the foreign country and, if you do not have a second foreign country, you can move on to part four, states the IRS.
Part four of Form 8840 is the area in which you can establish your significant contacts to the foreign country. Include where your family lives, where your car is located, what bank you use and other personal information. Once you fill out all of this information, you must attach it to Form 1040NR or 1040NR-EZ. If you do not have either of these forms, simply mail Form 8840 to the Department of the Treasury in Austin, Texas, notes the IRS.