American citizens and green card holders, including people who have the right to U.S. citizenship, are required to file a federal income tax return each year declaring their worldwide income, wherever in the world they live. They may also have to pay U.S. taxes.

In principle, tax treaties are intended to prevent double taxation on the same income by two different countries.

The U.S. has signed tax treaties with around 70 other countries (with more in the pipeline). However, in general, these treaties protect foreign nationals living in the U.S. from double taxation much more than US citizens living abroad.

This is because most U.S. tax treaties contain a ‘Saving Clause’, which essentially guarantees the U.S. the right to tax its citizens regardless of the other provisions of the treaty.

When exactly are tax treaties beneficial to U.S. expats?

There are however circumstances when a tax treaty can benefit Americans living abroad.

In particular, many U.S. tax treaties prevent the U.S. from taxing foreign-sourced dividend, interest and royalties income that has already been taxed in the expat’s country of residence. This will be beneficial for an expat who receives these types of income and lives in a host country that taxes them at a lower rate than the U.S. would.

Another example of when a tax treaty can benefit U.S. citizens is if they are living abroad as a researcher, student, teacher or trainee. Most U.S. tax treaties contain provisions to exempt these groups from having to pay taxes in their host country, providing their residence abroad is temporary, typically no longer than 2-5 years, as defined in each tax treaty.

Two important points to make though are that all tax treaties are different, so if you think you might benefit from a tax treaty provision, you still have to check the particular treaty, and secondly, that the benefits of a tax treaty aren’t applied automatically, but instead have to be claimed by filing form 8833 when you file your federal income tax return.

So how can expats avoid double taxation?

So in general, the usefulness of tax treaties to protect most U.S. expats from double taxation is limited. The good news however is that there are a number of other ways to do this.

For expats who earn up to around $100,000, the Foreign Earned Income Exclusion lets them exclude their income from U.S. taxation.

The exact limit rises a little each year, but expats who earn a little over this amount and who rent their home abroad can exclude the value of a proportion of their rental expenses by claiming the Foreign Housing Exclusion. Both the Foreign Earned Income Exclusion and the Foreign Housing Exclusion can be claimed by filing form 2555 along with a federal return.

Another way of avoiding double taxation is by claiming the Foreign Tax Credit, which offers a $1 U..S tax credit for every dollar of tax already paid in another country. This is often a good strategy for expats who have paid more tax abroad than they would owe to the U.S., as they can claim more U.S. tax credits than they need and carry their excess credits forward for future use.

It’s probably clear by now that expats always have to file to claim the exemptions that let them avoid double taxation, and also that expats should strategize which exemptions they claim depending on their circumstances (to file most beneficially in terms of tax efficiency). It may or may not be beneficial to take advantage of the provisions of a tax treaty a part of this strategy, again depending on their circumstances.

Catching up

Expats who weren’t aware that they have to file a U.S. tax return while living abroad, perhaps because they thought they were protected by a tax treaty, should consider catching up with their U.S. tax filing using the Streamlined Procedure. The Streamlined Procedure is an IRS amnesty program that lets expats catch up without facing any penalties, while also letting them backdate the exemptions (and tax treaty provisions, if applicable) that allow them to avoid double taxation.