GB WHT to a US supplier---tax not calculated

Client has a requirement to apply GB WHT 0% if Supplier is from US.

Set-up:

Place of Supply: Bill-from

Tax Registration- Bill From

Tax Determining Factor Set:

Tax Condition Sets:

Tax Rule: Tax Applicability and Tax Status Rule

Supplier used: Site address is in US, with Proc BU of UK, Allow Tax Applicability is enabled

Did I miss to configure something? Is there anything else I need to check from the supplier? Thanks