Self-Employment Tax and SE Income for Expats

Self-employed expats face the most complex tax optimization problem. The Foreign Earned Income Exclusion does not shield self-employment tax, while Totalization Agreements may eliminate double contributions to social security systems.

Self-employment tax is the surprise that catches most expats. The Foreign Earned Income Exclusion can shield up to $126,500 (2024) of earned income from federal income tax. But it does not exclude that income from self-employment tax -- the 15.3% combined Social Security and Medicare tax (12.4% + 2.9%) on net self-employment earnings. This means you can owe thousands in SE tax even when your income tax liability is zero after the FEIE.

Totalization Agreements can eliminate the double hit. If you lived in a country with a US Totalization Agreement and paid into that country's social security system, you may be exempt from US self-employment tax on those earnings. You need a Certificate of Coverage from the foreign country's social security administration to claim this exemption.

The Foreign Tax Credit works differently for SE tax. You cannot use the FTC to offset self-employment tax directly. However, if you skip the FEIE and instead use the FTC for income tax purposes, the math sometimes works out better overall because the FTC can offset income tax dollar-for-dollar while the FEIE leaves SE tax untouched.

The tradeoff: Self-employed expats face the most complex tax optimization problem -- three variables (FEIE, FTC, SE tax) that interact differently depending on your income level, foreign tax rate, and Totalization Agreement status. A CPA models all scenarios to find the lowest total liability.