Social security abroad follows your work, income tax follows your residence
Income tax and social contributions are separate systems with separate tests. Income tax mostly follows your tax residency, set by days, a home and your ties; social security mostly follows the place where you work, and for someone who moves the 2 answers often differ.
That is why digital nomad taxes come with a second bill that can sit in a different country. A US freelancer living in Tbilisi pays Georgian tax on work done in Georgia and US self-employment tax as well, because US coverage follows self-employed citizens abroad even with no business in the US (SSA).
The paperwork is separate too. A tax residency certificate proves where you pay income tax as a resident; an A1 or a certificate of coverage proves which social security system you belong to, and neither stands in for the other.
Which country you pay social security in as an employee
The default almost everywhere is the country where the work is done. Inside the EU only 1 system covers you at a time (European Commission), and a posting of up to 24 months is the time-limited exception: the employer requests an A1 certificate before the posting starts, and you stay in the home system (European Commission FAQ).
An employee working in 2 or more EU countries is insured in the country of residence if at least 25% of working time or pay is there, and otherwise where the employer's head office is (Your Europe). The same coordination rules apply across the EEA and Switzerland.
Teleworkers have a further option. 23 states have signed a framework agreement on cross-border telework that lets employer and employee jointly ask to stay in the employer's system when the employee teleworks less than 50% of the time from their own country of residence.
A Lisbon resident on a Madrid payroll
Stays in Spanish social security
Lives in Lisbon, works for a Madrid company and spends 3 weeks in every 5 at the Madrid office, teleworking from home the rest of the time. Telework in Portugal is 40% of her time and both countries signed the framework agreement, so on a joint request she stays in the Spanish system.
Moves into Portuguese social security
Same job, but she now spends only 2 weeks in 5 in Madrid and assumes nothing changed. At 60% telework the framework agreement no longer applies, and with more than 25% of her work in her country of residence, Portugal's system covers her.
Outside Europe, 2 countries can both claim an employee. The SSA keeps US citizens and residents employed abroad by an American employer in US Social Security for as long as the assignment lasts, and for an employee working remotely from another country the host country can add its own contributions on top. HMRC keeps Class 1 National Insurance going for the first 52 weeks in a country with no agreement when the employer has a UK place of business and the employee is ordinarily resident in the UK and was living there just before starting work abroad.
Which country you pay social security in as a self-employed nomad
Inside the EU the rules for freelancers mirror the employee ones. A self-employed person working in 2 or more countries is insured in the country of residence if a substantial part of the work, at least 25% of working time or income, is there, and otherwise where the center of interest of the activities lies; for the self-employed, turnover and the number of services provided can also count toward the 25% (Your Europe).
A freelancer who goes to do similar work in another EU country for a while can stay in the home system with a PD A1, which is issued for up to 24 months (Your Europe). A freelancer who settles in the new country joins its system.
Outside the EU, each country's own law decides. In the 12 nomad bases below, from the Index country data, the answers for a foreign freelancer range from nothing compulsory to 20% of earnings, up to a cap, in Brazil:
Compulsory social contributions for a foreign freelancer in 12 nomad bases
| Country and scheme | Compulsory for a foreign freelancer? | What applies |
|---|---|---|
| Georgia's pension rules | No | Funded pension is voluntary; 4% of income if you opt in |
| Mexico's social security | No | Own-account workers may join IMSS voluntarily |
| Paraguay's IPS | No | Voluntary pension at 13% of a base you choose, at least 1 minimum wage |
| UAE social security | No | Does not apply to non-GCC nationals |
| Singapore's MediSave | No | Compulsory only for self-employed citizens and permanent residents |
| Thailand's social security | No | Charged on employees' wages only |
| Dominican Republic social security | No | The regime for the self-employed has not started |
| Costa Rica's CCSS rules | No | Law 10008 sets no duty to contribute to the CCSS |
| Colombia's contributions | Yes | Health 12.5% and pension 16%, both on 40% of income; a foreigner who pays into a home pension, or is not resident, owes health only |
| Hong Kong's MPF | Yes | 5% of relevant income, capped at HKD 18,000 (about $2,290) a year, paid into your own retirement account |
| Philippine SSS | Yes | 15% of the monthly salary credit, at most PHP 63,000 (about $1,010) a year; no nationality condition |
| Brazil's INSS | Yes | 20% of earnings, at most BRL 20,341 (about $3,910) a year in 2026 |
Europe is where the bill gets large, and the base matters as much as the rate. On $100,000 of revenue, contributions take 3.96% of profit under UK Class 4 National Insurance and 26.07% under Italy's separate INPS scheme. Spain's self-employed quota has a 31.5% headline rate on a monthly base chosen by income bracket, so it takes 8.76% of profit, while Portugal's freelancer contributions, 21.4% on 70% of revenue, take 17.62%.
Source: Nomad Tax Index country data Headline rates differ from these shares because each country charges its own base: Spain 31.5% on a monthly base chosen by income bracket, Portugal 21.4% on 70% of revenue, Czechia 29.2% on 55% of profit after flat expenses. Hungary includes its social contribution tax, Czechia and Romania include health insurance, Switzerland includes administration costs, Bulgaria is capped at the 2026 maximum insurable income, and Ireland blends the 2026 PRSI rates.
Show the numbers
| Share of profit | |
|---|---|
| Italy | 26.1% |
| Hungary | 18.2% |
| Portugal | 17.6% |
| Romania | 13.6% |
| Czechia | 11.8% |
| Switzerland | 10.5% |
| Bulgaria | 9.8% |
| Spain | 8.8% |
| Ireland | 4.2% |
| United Kingdom | 4% |
Bilateral social security agreements outside the EU
Outside the EU coordination area, pairs of countries sign agreements that put a worker in 1 system and let contributions in both count toward a pension. The US calls them totalization agreements and has 31 in force, from Italy in 1978 to Romania on September 1, 2026 (SSA).
The UK's arrangements with the EU, Iceland, Liechtenstein, Norway and Switzerland keep a posted worker in UK National Insurance for up to 2 years (GOV.UK). Beyond Europe, its agreement countries include Canada, India, Israel, Japan, the Philippines, South Korea, Turkey and the US (HMRC).
Self-employed Americans gain the most, because the IRS charges self-employment tax abroad on the same rules as at home and the foreign earned income exclusion does not reduce it. Under the US agreement with the UK, a self-employed person is covered only by the country where they ordinarily reside (UK-US agreement, Article 4 as revised), so a US freelancer living in London pays UK contributions, and self-employment tax abroad stops for the years covered by the UK certificate.
No agreement: when you pay into 2 systems
Without EU rules or an agreement, nothing stops 2 countries from charging contributions on the same income, and neither has to count the periods you paid into the other toward a pension.
A US freelancer in the Philippines pays twice
The US has no agreement with the Philippines. A US citizen freelancing from Manila on $50,000 of profit owes $7,065 of US self-employment tax and the SSS maximum of PHP 63,000 (about $1,010) on the same income, about $8,070 a year in all.
Short stints rarely pay off in the second system. The SSA points out that a worker who contributes abroad for a few years may never qualify for a benefit there, so for practical purposes those contributions are lost.
What happens to your pension when you work in several countries
Inside the EU, each country where you were insured pays its own pension for its share of your career, and a country with a minimum contribution period must count the periods you worked in other EU countries when it decides whether you qualify (Your Europe). If you were insured in a country for less than 1 year, it may pay no pension at all; those months are then counted by the countries where you worked longer, and you claim through the pension authority where you live or last worked (Your Europe).
US agreements work the same way in outline: the SSA adds foreign credits to at least 6 quarters of US coverage to reach the 40 a retirement benefit usually needs, and pays only for the US share.
Stopping contributions: voluntary payments and the cost of a gap
Plenty of nomads end up in no system at all: they leave the home system, settle in a base with nothing compulsory, and build no pension anywhere. Some home countries sell voluntary contributions to fill the gap, and the UK closed its cheaper option for people abroad in April 2026.
The gap has a price. The full new UK State Pension is £241.30 (about $320) a week and needs 35 qualifying years (GOV.UK), so each year missing from those 35 takes £358.50 (about $475) a year off the pension for life. A year of voluntary Class 3 costs £956.80 (about $1,270), at £18.40 (about $24) a week (GOV.UK).
| Voluntary Class 2 for periods abroadStill open to people treated as self-employed in the UK under a social security agreement | Closed from April 6, 2026 |
|---|---|
| Voluntary Class 3 for periods abroadNew applicants need 10 continuous years of UK residence or 10 qualifying years | Open |
| Class 3 for 2026 to 2027£18.40 (about $24) a week | £956.80 (about $1,270) a year |
| Extra cost of Class 3 over Class 2 | £767 (about $1,020) a year |
| Current Class 2 payers moving to Class 3The 10-year test does not apply to them | Apply before April 6, 2027 |
From HMRC's guidance on voluntary contributions abroad, published March 16, 2026, and the 2026 to 2027 rates on GOV.UK.
Settling your social security before you move
Social security steps for a move abroad
- List every country you will work from this year, and whether you will be employed or self-employed in each.
- Check whether those countries share EU coordination rules or a bilateral agreement with your home country.
- As an employee, ask your employer to apply for an A1 or a certificate of coverage before you leave.
- As a freelancer, register for contributions where the rules place you, or request your own certificate of coverage.
- Keep every certificate with your tax records; a US freelancer attaches a copy to the US return each year.
- Decide whether to keep paying voluntarily at home, and note the application deadline.
David's note
I would treat social security as a pension decision first and a tax line second. Paying into nothing for 10 years looks like a saving until you price the pension it would have bought, so I would choose the system on purpose, voluntary contributions included.
