Tax Treaty

A tax treaty is a formal agreement between two countries, in the United States' case an income tax treaty, that coordinates how the two tax systems apply to people and income that cross the border between them. Its purpose is to prevent the same income from being fully taxed by both countries and to prevent it from escaping tax altogether. It does this by assigning the primary right to tax particular kinds of income to one country or the other, reducing the rates of tax that may be withheld at the source, and setting rules to resolve conflicts such as when both countries would treat the same person as a resident.

The United States has income tax treaties with roughly 60 countries. Each is negotiated separately, so the details differ, but most follow the structure of the US Model Income Tax Convention: articles on business profits, dividends, interest, royalties, pensions, students, and government service, plus administrative articles on residency, non-discrimination, and the exchange of information. For an American living abroad, though, the single most important provision is often the one that takes benefits away.

The saving clause is the provision every US citizen abroad has to understand, because it undoes most of the treaty for them. Nearly every US tax treaty contains a clause under which the United States reserves the right to tax its own citizens and residents as if the treaty had not entered into force. The practical effect is that a US citizen generally cannot use the treaty to reduce US tax on most of their income, even income the treaty appears to assign to the other country. The saving clause carries a short list of exceptions, typically covering items like certain pensions, child-support and social-security provisions, and relief from double taxation, but the default is that the treaty works for the foreigner in the United States far more than for the American abroad. This is why the foreign tax credit, not the treaty, is usually the tool that actually prevents double taxation for a US citizen.

Reduced withholding is the benefit treaties deliver most reliably. When one country's resident receives dividends, interest, or royalties from the other, the source country would ordinarily withhold tax at its statutory rate, which for US-source dividends paid to a foreign person is 30 percent. A treaty commonly reduces that to 15 percent or less on dividends and often to zero on interest and royalties, provided the recipient qualifies and, in the United States, generally documents the claim on a Form W-8. This is where a treaty most directly saves money, and it flows in both directions.

The residency tie-breaker resolves a genuine conflict. Two countries can each conclude, under their own domestic rules, that the same person is a resident, which without a treaty would expose the person's worldwide income to both. Treaties supply a cascading test, usually permanent home, then center of vital interests, then habitual abode, then nationality, and finally mutual agreement between the tax authorities, to assign residency to one country for treaty purposes. For a US citizen the tie-breaker's value is again limited by the saving clause, but for many resident aliens it is decisive.

Claiming a treaty position that overrides the code has to be disclosed. When a taxpayer relies on a treaty to take a position contrary to US tax law, for example to exempt income the code would otherwise tax, the position generally must be disclosed to the Internal Revenue Service on Form 8833, the treaty-based return position disclosure. Failing to disclose a position that requires it carries a statutory penalty. Not every treaty benefit needs a Form 8833, and there are exceptions for routine items such as reduced withholding on certain investment income, but a substantive override of the code generally does.

In practice a treaty is applied income item by income item. For each type of income, you find the treaty article that covers it, determine which country the treaty gives the primary right to tax and at what maximum rate, check whether the saving clause pulls the benefit back for a US citizen, and, if you are overriding the code, disclose the position on Form 8833.

A hypothetical example of reduced withholding. Elena is a resident of a treaty country, not a US citizen, and owns shares in a US company that pays her a $10,000 dividend. Without a treaty, the United States would withhold tax at 30 percent, or $3,000. The treaty between her country and the United States caps withholding on portfolio dividends at 15 percent, so by giving the payer a completed Form W-8BEN claiming the treaty rate she has $1,500 withheld instead of $3,000, keeping an extra $1,500. Had Elena been a US citizen living in that country, the saving clause would generally have preserved full US taxation of the dividend, and she would have relied on the foreign tax credit rather than the treaty to avoid double tax.

A tax treaty is a background rule that either helps a given taxpayer or largely does not, depending mostly on citizenship.

What a treaty does well

• It reduces or eliminates withholding taxes on cross-border dividends, interest, royalties, and pensions, which is a direct and reliable saving.
• Its residency tie-breaker resolves the otherwise intractable case of two countries both claiming someone as a resident.
• It reduces double taxation and provides a mutual-agreement procedure for disputes the two authorities cannot otherwise resolve.

Where its help runs out

• The saving clause preserves US taxation of US citizens and residents, so the treaty does much less for an American abroad than its articles suggest.
• Each treaty is different, so a benefit available under one country's treaty may be absent from another's, and the analysis is item-by-item.
• Overriding the code on the strength of a treaty usually requires a Form 8833 disclosure, with a penalty for failing to file it.
• A treaty covers income tax only. It does nothing about Social Security taxation, which is the separate province of a totalization agreement.