The IRS released a new version of Form W-8BEN. The new version should be used by an individual responding to a withholding request from the US. It’s commonly used to note tax treaty benefits.
There is a disclaimer on the form: “For use by individuals. Entities must use Form W-8BEN-E.” There’s only one problem with that: Form W-8BEN-E has not been released yet; it’s still in draft form. I suspect that until the Form W-8BEN-E is released, an entity can use the Form W-8BEN.
The IRS also released a new version of Form W-8ECI. This is the form used by individuals and businesses who are foreigners with a business in the US; that is, income that is effectively connected with the US. Individuals and entities completing this form are required to complete a US tax return.
People receiving either of these forms should make sure they receive the new forms (dated by the IRS as February 2014). The old forms should no longer be accepted.