If an account is held by a nonresident alien or a foreign entity,1 Fidelity must have Certificate of Foreign Status on file for the account. This information is required for U.S. tax withholding purposes on income earned in your Fidelity account.
The W-8 certification is also required for U.S. tax withholding for distributions from retirement accounts (Traditional IRAs, SEP, SIMPLE).
You can complete your form online or print a blank form.