更新W-8BEN (TD Ameritrade) - 理財

今天收到 TDA 寄來的更新 W-8BEN 通知
但其中有一段是 "New this year"，
完整訊息如下：

You are now required to provide your Foreign Tax Identification Number (FTIN)
on Line 6 of the Form W-8BEN. If you do not have an FTIN, please complete a
Reasonable Explanation Form and submit it with your other required paperwork.
Note: If your country has an Intergovernmental Agreement (IGA) with the
United States and requires an FTIN, TD Ameritrade cannot accept the
Reasonable Explanation Form in lieu of your FTIN.

以前 W-8BEN 的 Line 6 (FTIN) 都是直接填 N/A
現在看起來是要填 N/A 的話
需要再填 Reasonable Explanation Form
這個表格就是有三個選項：

1) The country or jurisdiction where I am a tax resident does not issue
taxpayer identification numbers.
Provide country or jurisdiction:
2) I am not required to obtain a taxpayer identification number or equivalent
identification for the following reasons:
3) Others

不知道有沒有人已經填過了呢？
謝謝~


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