How tax treaty works
A tax treaty is the rulebook for tax overlap between two countries. Domestic law comes first: one country may claim you because you are resident, while the other claims income because it arose there. The treaty then says how those competing claims should be limited, shared, or relieved. It is most useful when read alongside both countries' domestic rules.
Common treaty articles deal with residence, business profits and permanent establishments, employment income, dividends, interest, royalties, capital gains, and methods for relieving double taxation. The residence article can contain a tie-breaker where two countries regard a person as resident. The dividend article may cap source-country withholding. A business-profits article may prevent source-country tax unless the foreign business has a permanent establishment there.
None of that means one tax return disappears. Treaties can leave the source country entitled to tax, while asking the residence country to grant a credit or exemption. A reduced withholding rate may require a residence certificate and beneficial-ownership evidence before payment. Anti-abuse provisions can deny benefits where an arrangement lacks the conditions the treaty requires.
Use the actual bilateral treaty, including protocols and effective dates. The OECD Model Convention is highly influential but it is not itself a treaty between you and a tax authority. For a cross-border transaction, identify the payer, beneficial owner, income type, residence status, local permanent establishment, and documents needed before cash moves.
Why it matters for founders and expats
- A treaty can reduce withholding, determine treaty residence, and limit source-country tax.
- The actual treaty and its protocol matter; OECD Model wording is a template, not the law between every pair of countries.
Practical examples
Dual resident
Two domestic systems claim an individual. The treaty may assign residence for treaty purposes through a tie-breaker sequence.
Dividend withholding
A treaty can cap tax withheld on a cross-border dividend when the recipient satisfies its residence and beneficial-ownership conditions.
Common misconceptions
A treaty makes foreign income tax-free.
Usually it allocates a taxing right or requires credit or exemption; both countries can still have a role.
The OECD Model is my treaty.
It is a model. Read the signed treaty, protocols, effective dates, and each country's implementing rules.
Frequently asked questions
Do treaties override domestic law?
Their effect depends on each country's constitutional and implementing rules, but they generally limit rather than create domestic taxing rights.
Last updated August 2026. Educational definition only — not tax or legal advice.