Example:

A single member LLC wholly owned by a U.S. resident is treated as fiscally transparent in the U.S. but is treated as fiscally nontransparent in Country X, where it earns income subject to tax by Country X. The recipient of the entity's Form 6166 in Country X questions the substance of the form issued, including whether the proper party is named on the certification, and makes an inquiry about the U.S. certification process.

If a foreign withholding agent refuses to accept a Form 6166 Residency Certification provided by a U.S. taxpayer, the Treaty Assistance and Interpretation Team (TAIT) within the U.S. Competent Authority office must be contacted if the refusal is based on regulations or legislation issued by the foreign country from which treaty benefits are claimed. Prior to contacting TAIT, it must be determined if the rejection is based on:

A foreign government's refusal to accept Form 6166

The need to supplement the certification with additional disclosures

The need to specifically modify Form 6166 following the laws of the foreign jurisdiction