Foreign-Source vs U.S.-Source Income: Why It Matters
Reviewed by the Fairlight Accounting cross-border tax team — U.S. & Canadian Tax Desks
Income sourcing is the set of U.S. rules that label each item of income as either U.S.-source or foreign-source. For a U.S. citizen abroad the label doesn't change whether the income is taxable — everything is — but it decides whether the two main tools for avoiding double tax can reach it. The foreign earned income exclusion applies only to foreign-source earned income; the foreign tax credit is limited to U.S. tax on foreign-source income. Get the source wrong and the tools stop working.
On this page
- Why does source matter if everything is taxable anyway?
- How are wages and self-employment income sourced?
- How are interest and dividends sourced?
- How are rents and property gains sourced?
- How are gains on stocks and other personal property sourced?
- How are pensions and Social Security sourced?
- What goes wrong in practice?
- Frequently asked questions
- Next step
Why does source matter if everything is taxable anyway?
Two reasons:
- The exclusion covers wages and self-employment income only when the work is performed abroad. U.S.-source earned income can't be excluded.
- The credit limit is the U.S. tax on your foreign-source income, computed separately for passive income and general income. Foreign tax paid on income the U.S. treats as U.S.-source generates credit you cannot use — a frequent cause of real double taxation.
How are wages and self-employment income sourced?
By where the work is physically performed, regardless of who pays or where the money lands. A remote employee of a U.S. company working from Spain earns Spanish-source wages. A consultant who spends twenty workdays in New York and two hundred abroad has twenty days of U.S.-source income that cannot be excluded. Keep a workday log; the allocation is by days unless a better method is documented.
How are interest and dividends sourced?
- Interest by the residence of the payer: interest from a U.S. bank or U.S. company is U.S.-source even if you live abroad; interest from a foreign bank is foreign-source.
- Dividends by the country of incorporation of the paying company: U.S. corporate dividends are U.S.-source; dividends from a German or Japanese company are foreign-source. Dividends from a U.S. mutual fund are U.S.-source even if the fund holds foreign stocks, which surprises many expats.
How are rents and property gains sourced?
By where the property is located. Rent from a flat in London is foreign-source; rent from a condo in Miami is U.S.-source. Gains on real estate follow the same rule.
How are gains on stocks and other personal property sourced?
Generally by the residence of the seller — so a U.S. citizen genuinely resident abroad has foreign-source gains on sales of stock, even U.S. stock, provided the country of residence taxes the gain at or above the minimum rate the statute sets; a gain taxed lightly or not at all abroad stays U.S.-source. This is one of the few places where moving abroad flips the source of U.S. investments, and it matters when the country of residence taxes those gains: the credit becomes available. Exceptions apply to inventory, depreciable property, and certain other categories.
How are pensions and Social Security sourced?
Pensions are sourced by where the services that earned them were performed, which often means a mix. U.S. Social Security is U.S.-source. Treaties frequently override these defaults for pensions and government benefits, assigning taxing rights to one country or the other.
What goes wrong in practice?
- Claiming the exclusion on wages for days worked in the U.S.
- Treating U.S. mutual fund dividends as foreign because the fund is "international."
- Paying foreign tax on U.S.-source income (common with U.S. Social Security taxed by the country of residence) and finding the credit unusable in the passive basket.
- Forgetting that a treaty may re-source certain income to make credits work — Form 8833 may be needed to claim it.
Frequently asked questions
I'm paid by a U.S. company into a U.S. bank account. Isn't that U.S. income?
Not if the work was done abroad. Payer and bank location don't determine source for personal services; the place of performance does.
My foreign country taxes my U.S. dividends. Can I credit that tax?
Only against U.S. tax on foreign-source passive income. Unless a treaty re-sources the dividends, the credit may be stranded.
Does the source rule affect the FBAR or Form 8938?
No. Those depend on where the account is held, not on the source of what's in it.
Is there a form that shows the sourcing?
Form 1116 allocates income and tax by source and category; Form 2555 reports foreign earned income and the days abroad that support it.
Next step
Fairlight Accounting handles U.S. domestic, cross-border (U.S.–Canada), and international tax returns, plus bookkeeping, payroll, and CFO advisory. If your credits or exclusion aren't working the way you expected, the sourcing is usually why — our U.S. Tax Desk can trace each income item and fix the allocation. See pricing or book a free fit call.
Cross-border taxes, handled in one place
U.S. and Canadian filings prepared together by our U.S. and Canadian Tax Desks.
Book a free fit call