Foreign Account Tax Compliance Act (FATCA)

Why do I need to provide documents that I already gave to IBKR?
I responded to your email and provided the requested documents. Now I received an email saying my response was insufficient to resolve the issue. Why?
I submitted a proof of address and I received an email that the document submission did not resolve the issue. Why?
Tax treaty benefits
My address is inside a treaty country but you are showing the wrong address. What should I do?
FATCA FAQs - Issues Involving Mismatch Between Tax Treaty Country and Address
I have a U.S. Green Card but am not a U.S. taxpayer. What additional information or documentation do I need to provide to ensure you can accept my Form W-8BEN?
Are Non-US residents subject to withholding for tax purposes?
The information in your records is incorrect. I have no connection to the U.S. What can I do to remedy this situation?
I live in Hong Kong and chose China as my tax treaty country on my Form W-8BEN but the proof of identity I sent is not sufficient. Why?
The address or telephone you noted in your email is out-of-date. I have since moved out of the United States. What should I do?
FATCA FAQs - General
FATCA FAQs - Issues involving U.S. passport or other evidence of U.S. citizenship
I submitted IRS Form W-8. Why do I have to submit additional documentation?