Nonresident alien taxation

This page summarizes how a US nonresident alien (NRA) is taxed when investing in US domiciled ETFs. Nonresident aliens can be subject to both US withholding taxes and US estate taxes.

Who is a nonresident alien (NRA)?
If you are an alien (not a US citizen), you are considered a nonresident alien unless you meet one of two tests. You are a resident alien of the United States for tax purposes if you meet either the green card test or the substantial presence test for the calendar year (January 1-December 31).

Are capital gains taxable for a nonresident alien?
No. Capital gains from US domiciled ETFs are not taxable by the IRS. According to IRS Publication 519 :

Also, according to a reply received for a paid consultation with Greenback Expat Tax Services Limited:

US domiciled ETFs tax withholding
Tax withholding is applied to dividends paid to you as an investor. It does not apply to capital gains, nor to interest payments. The standard rate is 30%. This can be lowered (usually to 15%) if your country of residency has a tax treaty with the US, by submitting a W-8BEN form via your broker.

Estimating tax withholding leakage
Other than the tax withholding that shows on your brokerage account's statement, the fund itself gets taxes withheld on dividends received. This is usually applicable to funds holding international equities. This number affects investors, but is mostly invisible unless you look at the annual reports.


 * For more information see: Estimating Level 1 dividend tax withholding paid by US domiciled funds.

TD Ameritrade tax withholding experiment
A test in 2015 using a TD Ameritrade account and a selection of US domiciled ETFs: MUB, BIV, LQD, BNDX, VIG, VTI and VXUS, shows that all had tax withheld at 30% from the dividends distributed, with the exception of MUB and VXUS. MUB holds US municipal bonds, which are tax-exempt from US federal taxes. VXUS holds stocks of non-US companies.

US estate taxes
If your home country does not have an estate tax treaty with the US, you risk becoming liable for US estate taxes. While the US has an extensive network of income tax treaties, only a handful of countries have estate tax treaties with the US.

Even where a treaty protects nonresident investors from US estate tax, there are still hurdles and delays in accessing US domiciled holdings:

A US estate tax treaty may provide protection from US estate taxes to a level equivalent to that allowed to US citizens, but the presence of a US estate tax treaty does not guarantee that this is the case. US nonresident aliens considering holding US domiciled ETFs and other US situated assets should check any applicable US estate tax treaty details very carefully before proceeding. Note that residency is not normally a sufficient condition for using a US estate tax treaty. This type of treaty is generally controlled by domicile, a legal concept that, although it includes residency as one of its components, is different and distinct from residency.

Local estate taxes may apply as well, and in the absence of a US estate tax treaty this can cause double taxation. In addition, some US estate tax treaties do not provide for estate tax credits, and this may also cause double taxation.

Foreign Account Tax Compliance Act (FATCA) and NRAs
Regarding non-US clients of a foreign financial institution (FFI) who will not provide the documentation needed for FATCA:

To avoid running into FATCA withholding issues, use a FATCA-compliant broker where possible, and make sure your W-8BEN form is up-to-date. Most US brokers and larger international ones are FATCA-compliant. You can confirm by checking with your brokerage firm if you are investing in US domiciled securities.