Only two countries in the world tax their citizens on worldwide income no matter where they live: the United States and Eritrea. Most other countries that tax worldwide income do so based on residency, meaning the obligation kicks in once you’ve spent enough time inside their borders (commonly more than 183 days a year) and ends when you leave. A smaller group taxes only income earned within the country itself, ignoring anything you earn abroad. Which system applies to you is what determines whether moving overseas actually changes your tax bill or simply adds a second government to answer to.
The Three Systems at a Glance
Countries generally fall into one of three camps when it comes to reaching income earned outside their borders.
Citizenship-based taxation follows your passport. You owe tax on your global earnings because of who you are, not where you are. Residence-based taxation follows your feet: once you qualify as a tax resident, the country claims a share of everything you earn worldwide, and once you leave for good, the obligation stops. Territorial taxation ignores foreign income entirely and taxes only what originates inside the country.
The vast majority of countries use the residence-based model. A handful use territorial rules. Only two use citizenship.
Citizenship-Based Taxation: The U.S. and Eritrea
The United States is the prominent example. If you hold a U.S. passport or a green card, the IRS expects you to report every dollar you earn anywhere in the world, even if you haven’t set foot in the country for years. That covers wages, investment returns, rental income, business profits, and essentially every other form of income.1Internal Revenue Service. U.S. Citizens and Resident Aliens Abroad The legal footing is broad. The Internal Revenue Code defines gross income as “all income from whatever source derived,” and the Supreme Court affirmed in 1924 that Congress can tax citizens on foreign income because citizenship itself confers protections worth paying for.2Cornell Law Institute. Cook v. Tait, Collector of Internal Revenue
Eritrea is the other. It levies a flat 2% tax on the net income of Eritreans living abroad.3Eritrean Embassy. Recovery and Rehabilitation Tax Enforcement looks nothing like the American model. Eritreans who don’t pay face denial of passport renewals, consular services, and documents such as birth or marriage certificates, and some are effectively barred from returning home to visit family. The tax is often collected at embassies as a condition of receiving any government service.
Tax Treaties Don’t Erase the U.S. Obligation
A common misconception is that U.S. tax treaties exempt Americans abroad from filing at home. They don’t. Nearly every U.S. tax treaty contains a “saving clause” that preserves each country’s right to tax its own citizens and residents as if the treaty didn’t exist.4Internal Revenue Service. Tax Treaties Can Affect Your Income Tax Treaties still matter for things like reduced withholding on dividends, interest, and royalties. But the core duty to report and pay U.S. tax on worldwide income survives the treaty for every citizen and green card holder.
Residence-Based Countries and the 183-Day Rule
Most countries use residency as the trigger. Once you qualify as a tax resident, that government wants a full accounting of your global income. The specific test varies, but a common benchmark is spending more than 183 days inside the country during a 12-month period. Australia is a straightforward example: if you’re physically present for more than half the income year, you’re generally treated as a resident unless your usual home is clearly elsewhere.5Australian Taxation Office. Your Tax Residency
Countries using residence-based worldwide taxation include most of the world’s largest economies: the United Kingdom, Canada, Germany, France, Japan, India, South Korea, China, Brazil, Mexico, Italy, Spain, the Netherlands, and Sweden, among many others. Some apply stricter tests than a simple day count. The UK’s Statutory Residence Test weighs several factors including your ties to the country. Japan can treat you as a resident with fewer days present if your permanent home is there. The 183-day figure is useful shorthand, not a universal rule.
The real advantage of a residence-based system, compared to citizenship-based taxation, is that the obligation ends when you leave. A Canadian resident who moves abroad permanently stops owing Canadian tax on foreign income from that point on. That creates genuine flexibility for people willing to relocate.
Leaving Isn’t Always Free: Exit Taxes
Countries know that residents may pack up specifically to escape tax on accumulated wealth, and several have built safeguards. Canada’s is well known: when you cease to be a Canadian resident, most of your property is treated as if you sold it at fair market value on the day you left, and the resulting capital gains are taxable on your final Canadian return.6Government of Canada. Dispositions of Property for Emigrants of Canada Exceptions cover Canadian real estate, retirement accounts, and certain trust interests. Canada also lets you defer payment until you actually sell later, though you’ll need to post security if the deferred tax exceeds $16,500 federally.
Australia, Germany, and several other European countries have comparable mechanisms. Residence-based taxation is more flexible than the citizenship version, but leaving a country where you’ve built substantial wealth still carries a cost.
Territorial and Remittance-Based Countries
A smaller group of countries operates on a purely territorial basis. They tax only income that originates inside their own borders and ignore what you earn elsewhere. Notable examples include Hong Kong, Panama, Costa Rica, Paraguay, Guatemala, and Bolivia. These jurisdictions can be attractive to entrepreneurs and investors whose income comes from international sources.
Singapore and Thailand use a variation called remittance-based taxation. Foreign income is taxed only if you bring it into the country. Earn abroad, keep the money in a foreign account, and it’s generally left alone locally. The distinction matters: territorial systems ignore foreign income entirely, while remittance systems ignore it only until the money crosses the border.
For Americans and Eritreans, moving to a territorial country doesn’t eliminate the home-country tax bill. It does mean there won’t be a local tax layered on top, which simplifies things.
Digital Nomad Visas Don’t Override the Home Country
A growing number of countries now offer digital nomad visas with favorable local tax treatment. Croatia and Estonia exempt digital nomad visa holders from local tax on foreign-sourced income. Greece offers a 50% tax reduction for seven years. Spain’s Beckham Law allows qualifying new residents to pay a flat 24% on Spanish-source income and nothing on foreign income for up to six years. These programs are designed to attract remote workers. They do not override your home country’s rules. An American on a Croatian digital nomad visa still owes U.S. tax on worldwide income; the Croatian exemption just means Croatia won’t stack a second bill on top.
What This Means if You Hold a U.S. Passport
Because the U.S. is one of the two countries that tax by citizenship, most people searching this question are asking a follow-up: does moving abroad actually help? The honest answer is that relocation changes the second country in the equation, not the first. You’ll still file with the IRS. What relocation does affect is whether you end up paying the same income twice, and Congress created two main mechanisms to prevent that.
The Foreign Earned Income Exclusion
The Foreign Earned Income Exclusion lets qualifying taxpayers exclude up to $132,900 of foreign wages and self-employment income from U.S. tax for 2026, with the figure adjusted annually for inflation.7Internal Revenue Service. Figuring the Foreign Earned Income Exclusion If both spouses work abroad and each qualifies independently, each can claim the full amount.
To qualify, you pass one of two tests. The Physical Presence Test requires being outside the United States for at least 330 full days during any 12-month period. The Bona Fide Residence Test requires establishing a genuine home in a foreign country for an entire uninterrupted tax year.8Internal Revenue Service. Foreign Earned Income Exclusion The presence test is easier to document. The residence test is more flexible on travel but harder to prove because it turns on facts like where your permanent home is and what ties you keep abroad. You claim the exclusion on Form 2555.9Internal Revenue Service. About Form 2555, Foreign Earned Income
The Foreign Tax Credit
The Foreign Tax Credit works differently. Instead of reducing the income subject to U.S. tax, it directly reduces your U.S. tax bill by the amount you’ve already paid to a foreign government. You claim it on Form 1116 and convert foreign taxes into U.S. dollars using the exchange rate on the date you paid.10Internal Revenue Service. Instructions for Form 1116
Which mechanism is better depends on the country you’re in. The credit tends to win in high-tax countries: if you’re already paying 40% to France, offsetting your U.S. bill dollar-for-dollar with French tax paid often wipes out the U.S. liability entirely. The exclusion tends to win in low-tax countries, where there’s little foreign tax to credit but the exclusion still removes a large slice of income from U.S. reach. You can’t apply both to the same income, so the math depends on your specific numbers.
The Bottom Line on Where You Owe
If you’re a U.S. citizen or green card holder, worldwide taxation follows you until you formally exit the U.S. tax system, and moving to a low-tax or no-tax country abroad doesn’t change that on its own. If you hold citizenship anywhere else, worldwide taxation is triggered by where you live, and leaving that country (subject to any exit tax) genuinely ends the obligation. And if the country you’re considering moving to uses a territorial or remittance system, foreign-sourced income may be left alone locally, but you still need to check what your home country does with it. The country of your passport and the country of your residence each get a vote, and the question of which countries tax worldwide income only makes sense once you know which of those two roles each is playing in your situation.