All non-US persons wishing to trade US securities are required to complete a W-8 form from the US Internal Revenue Service (IRS) to demonstrate their tax residency and whether they meet the requirements for a reduced withholding tax rate. W-8 forms are not usually provided to the IRS.
Form W-8BEN
To claim tax treaty benefits between the US and your country of residence, you need to prove that you are not a US citizen.
Form W-8BEN: A Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting (Individuals).
You should complete Form W-8BEN if:
●You are not a US citizen, green card holder, or US resident.
●You are an international student in the US and have an F-1 visa, and you are not a US citizen or green card holder. (Even if you are considered a US resident).
Validity period
Form W-8BEN will remain in effect from the date it is signed until the last day of the following third calendar year unless any information in Form W-8BEN becomes incorrect due to changes in your circumstances.
For example, Form W-8BEN signed on September 30, 2015 is valid until December 31, 2018.