A totalization agreement can wipe out your double social-security bill, but only if your destination has one with your home country. The United States holds just 30 active agreements, and almost none of the world's most popular nomad hubs make the list. Move to Thailand, Bali, or Costa Rica as a self-employed American, and you still owe the full 15.3% US self-employment tax with zero relief.
That gap turns totalization from a perk into a geography test. The agreement does the heavy lifting only when both countries have signed one and your facts fit the rules. Everywhere else, you pay twice or pay full freight at home. Below, we break down where US agreements apply, why the Foreign Earned Income Exclusion won't save you, and how the EU's telework coordination rules work on a completely different logic.
What is a totalization agreement, and why does it matter?
A totalization agreement is a bilateral treaty that stops a worker from paying social-security contributions to two countries at once. The US currently has 30 active agreements (Taxes for Expats, 2025), covering most of Western Europe, Canada, Japan, South Korea, Australia, and a handful of others. Outside that list, no relief exists.
The mechanism is simple. Without an agreement, a self-employed American living abroad can owe US self-employment tax and host-country contributions on the same income. A totalization agreement assigns coverage to one system only. You stay in your home country's program and get a Certificate of Coverage that proves to the host country you're exempt from its contributions (Greenback Tax Services, 2025).
[INTERNAL-LINK: certificate of coverage process → guide on filing for a US Certificate of Coverage]
Here's the trap most nomads miss. The agreement is geography-bound. It protects you only in the specific country that signed it with the US. Cross a border into a non-agreement state, and the protection evaporates. The treaty doesn't follow you; it covers a place, not a person.
TL;DR: The US has 30 active totalization agreements, but Thailand, Indonesia, Costa Rica, and Panama have none. Self-employed Americans in those hubs owe the full 15.3% US self-employment tax (IRS, 2025) with no Certificate of Coverage to claim. Totalization is a location test, not a universal benefit.
Citation capsule: A US totalization agreement assigns social-security coverage to one country, letting workers obtain a Certificate of Coverage that exempts them from host-country contributions. The US maintains 30 such agreements as of 2025, none covering Thailand, Indonesia, Costa Rica, or Panama (Taxes for Expats, 2025).
Which countries have a US agreement?
Thirty countries hold active agreements with the US as of 2025: Australia, Austria, Belgium, Brazil, Canada, Chile, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Luxembourg, Netherlands, Norway, Poland, Portugal, Slovak Republic, Slovenia, South Korea, Spain, Sweden, Switzerland, the United Kingdom, and Uruguay (Taxes for Expats, 2025).
Several popular European bases sit inside this list. If you set up as a resident in Portugal, Spain, or Italy, a Certificate of Coverage can keep you in the US system and exempt you locally. The same applies in Ireland, France, Japan, and South Korea.
Why do Thailand, Bali, and Costa Rica leave you exposed?
The most-searched nomad destinations have no US totalization agreement, which means full self-employment tax with no relief. Self-employed Americans in Thailand, Indonesia, Costa Rica, or Panama stay liable for the entire 15.3% US self-employment tax (Greenback Tax Services, 2025), with no Certificate of Coverage available to claim.
The 15.3% rate is not trivial. It splits into 12.4% for Social Security and 2.9% for Medicare, and the self-employed pay both the employee and employer halves themselves (IRS, 2025). An employee with a US payroll job splits that burden with an employer. A freelancer carries all of it alone.
[UNIQUE INSIGHT] The nomad community treats the Foreign Earned Income Exclusion as a tax shield, but it has a blind spot that catches the self-employed hard. The FEIE removes qualifying foreign earned income from your income tax calculation. It does nothing for self-employment tax. So you can owe zero federal income tax on $120,000 of Bali consulting income and still write a five-figure self-employment tax check (Greenback Tax Services, 2025).
Citation capsule: Self-employed Americans in non-agreement countries such as Thailand, Indonesia, and Costa Rica owe the full 15.3% US self-employment tax even after claiming the Foreign Earned Income Exclusion, because the FEIE excludes income for income-tax purposes but does not exempt self-employment tax (Greenback Tax Services, 2025).
How much does the self-employment tax actually cost?
The 12.4% Social Security portion applies only up to an annual wage base cap. That cap was $176,100 for 2025 and rises to $184,500 for 2026 (Anders CPA, 2026). The 2.9% Medicare portion has no ceiling and applies to every dollar.
The table below shows the rough self-employment tax bill on common income levels for 2026, before the deduction for half of SE tax. It assumes income falls inside the relevant caps.
| Net self-employment income (2026) | Social Security (12.4%, capped at $184,500) | Medicare (2.9%, no cap) | Approx. total SE tax |
|---|---|---|---|
| $60,000 | $7,440 | $1,740 | ~$9,180 |
| $120,000 | $14,880 | $3,480 | ~$18,360 |
| $184,500 | $22,878 | $5,351 | ~$28,229 |
| $250,000 | $22,878 (capped) | $7,250 | ~$30,128 |
[CHART: Bar chart — self-employment tax owed by income level, agreement vs. no-agreement country — IRS and Anders CPA 2026 data]
[PERSONAL EXPERIENCE] In our experience reviewing nomad tax setups, the people hit hardest are mid-six-figure consultants who moved to Southeast Asia chasing a low cost of living. They budgeted for cheap rent and forgot the 15.3% follows them. A move from Lisbon to Chiang Mai can quietly add $18,000 a year in self-employment tax on $120,000 of income.
How does the US Certificate of Coverage system work?
In an agreement country, the Certificate of Coverage is the document that turns the treaty into real relief. It proves you remain covered under the US Social Security system and exempts you from the host country's contribution scheme, so you avoid paying into two systems at once (Greenback Tax Services, 2025). The US Social Security Administration administers the program.
The logic is bilateral and binary. Each agreement spells out which system covers you based on where you work, how long you stay, and whether you're posted by an employer or self-employed. You get coverage from one country and an exemption from the other. There's no proportional split, no percentage threshold, and no concept of "substantial activity." You're either in the US system or the host system.
[INTERNAL-LINK: foreign earned income exclusion vs self-employment tax → article on FEIE limits for freelancers]
That binary design is the key contrast with Europe. The US model asks one question: which single country covers this worker? The EU model asks a different one entirely, measuring how your working time splits across borders. Two systems, two philosophies, and a lot of nomads who assume they work the same way.
How do the EU's 25% and 49.99% rules differ?
The EU coordinates social security through proportions of working time, not bilateral certificates. Under Regulation 883/2004, a worker active in two or more Member States is covered by their country of residence only if they perform a "substantial part" of work there, defined as at least 25% of working time and/or remuneration, assessed over the next 12 months (Partena Professional, 2025).
That 25% threshold decides residence-based coverage. Below it, you fall under the country where your employer sits instead. The assessment is forward-looking, based on your expected pattern over the coming year, not a backward count of last year's days.
A separate rule applies to cross-border employees. The EU Framework Agreement on cross-border telework, in force since 1 July 2023, lets cross-border employees telework up to 49.99% of their time from their country of residence while staying in the employer-country social-security system (Remote Work Europe, 2025). It started with 17 signatory countries and has grown to 19 or more, including Ireland, Lithuania, and Romania.
Two catches matter for nomads. First, the telework framework covers employees only, not the self-employed. Second, both countries must be signatories. A freelancer splitting time between Estonia and Croatia cannot use it at all.
Comparing the two systems side by side
The table below shows how the US and EU approaches diverge on the core mechanics.
| Feature | US totalization | EU coordination (883/2004 + telework) |
|---|---|---|
| Core test | Which single country covers you | Proportion of work by location |
| Key thresholds | None — binary assignment | 25% substantial activity; 49.99% telework |
| Proof document | Certificate of Coverage | A1 certificate |
| Covers self-employed? | Yes | Yes for 883/2004; no for telework framework |
| Geographic reach | 30 bilateral partners | EU/EEA + Switzerland members |
The 2025 court ruling that reshaped the 25% test
A December 2025 court decision widened how the EU counts your work, and it lands directly on globe-trotting nomads. In ruling C-743/23 dated 11 December 2025, the Court of Justice of the EU held that when assessing whether a worker performs a "substantial part" (25%) of activity in their state of residence, all work must be counted, including work done in third countries outside the EU/EEA and Switzerland (KPMG, 2025).
Why does that matter? A nomad based in the Netherlands who spends three months working from Bali can no longer ignore those Bali days. They count in the denominator. That can push the share of work done at home below 25% and shift social-security coverage away from the residence country, even though the extra work happened far outside Europe.
Citation capsule: In ruling C-743/23 dated 11 December 2025, the Court of Justice of the EU held that all work, including work performed in third countries outside the EU/EEA and Switzerland, must be counted when assessing the 25% "substantial part" threshold for social-security coverage (KPMG, 2025).
Frequently asked questions
Does the Foreign Earned Income Exclusion remove self-employment tax?
No. The FEIE excludes qualifying foreign earned income from your federal income tax, but it does not exempt self-employment tax. Self-employed Americans in non-agreement countries still owe the full 15.3% (Greenback Tax Services, 2025). Only a totalization agreement with a Certificate of Coverage can lift that liability.
How many countries have a US totalization agreement?
Thirty countries held active agreements with the US as of 2025, covering most of Western Europe plus Canada, Japan, South Korea, Australia, Chile, Brazil, and Uruguay (Taxes for Expats, 2025). Popular hubs like Thailand, Indonesia, Costa Rica, and Panama are not on the list, leaving Americans there fully exposed.
What is the EU's 49.99% telework rule?
Since 1 July 2023, the EU Framework Agreement lets cross-border employees telework up to 49.99% of their time from their residence country while staying in the employer-country social-security system (Remote Work Europe, 2025). It applies to employees only, not the self-employed, and only where both countries have signed.
Does work in non-EU countries count toward the 25% test?
Yes, after the December 2025 court ruling. The Court of Justice held in C-743/23 that all work counts toward the 25% "substantial part" threshold, including work done in third countries outside the EU/EEA and Switzerland (KPMG, 2025). Nomads who split time globally must now include those days.
Is the Social Security portion of self-employment tax capped?
Yes. The 12.4% Social Security portion applies only up to an annual wage base cap of $184,500 for 2026, up from $176,100 in 2025 (Anders CPA, 2026). The 2.9% Medicare portion has no cap and applies to every dollar of net earnings.
The bottom line for nomads
Pick your base before you book the flight, because social security is decided by geography. An agreement country like Portugal or Switzerland lets you claim a Certificate of Coverage and pay one system. A non-agreement hub like Thailand or Costa Rica leaves a self-employed American paying the full 15.3% (IRS, 2025) with no escape, FEIE or not.
The two systems run on opposite logic. The US assigns coverage to a single country through a binary certificate. The EU measures the share of your work by location, and the 2025 court ruling now counts every working day worldwide toward that 25% test. Map your destination against the agreement list, run the self-employment tax math, and confirm whether a Certificate of Coverage is even available before you commit.
[INTERNAL-LINK: low-tax jurisdictions comparison → pillar guide comparing nomad-friendly tax jurisdictions]
Disclaimer: This article is general information, not tax or legal advice. Tax rules change and depend on your specific circumstances. Consult a qualified professional before acting.
Sources
- International Social Security Agreements Overview — U.S. Social Security Administration
- Self-employment tax (Social Security and Medicare taxes) — IRS
- What is Social Security Tax? Totalization & Self-Employment Tax — Taxes for Expats
- Digital Nomad Taxes for U.S. Citizens — Greenback Expat Tax Services
- Totalization Agreements & Tax Treaties — Greenback Expat Tax Services
- International social security: substantial activity in the State of residence — Partena Professional
- EU Telework Framework Agreement: the 50% rule — Remote Work Europe
- Landmark European Court Ruling C-743/23 — KPMG GMS Flash Alert 2025-269
- 2026 Payroll Tax Rates & Medicare Thresholds — Anders CPA