What Is Citizenship-Based Taxation?
Citizenship-Based Taxation is a tax system under which a country taxes citizens on worldwide income regardless of residence, applied chiefly under United States federal law.
Also known as: CBT, taxation based on citizenship.
How Citizenship-Based Taxation works
Citizenship-Based Taxation applies a country's income tax to every citizen on worldwide income wherever the citizen lives, so nationality rather than physical presence or residence decides the personal tax connection, and a move abroad does not by itself end filing or payment obligations. The IRS states that US citizens are subject to tax on worldwide income from all sources and that filing rules for income, estate and gift tax returns are generally the same at home or abroad. Double taxation is reduced, not removed, through mechanisms such as the foreign earned income exclusion, available to citizens with a foreign tax home who meet the bona fide residence test or the physical presence test of 330 full days in a 12-month period, and the foreign tax credit. Related reporting obligations, including FBAR and FATCA disclosures, also follow citizenship. The connection generally ends only on relinquishment of citizenship, which may trigger the expatriation tax rules for covered expatriates, while most other countries rely on residence-based rules, so the treatment of a given person depends on each state's domestic law.
Citizenship-Based Taxation vs Residence-Based Taxation
Unlike residence-based taxation, which ties worldwide tax liability to residence tests, citizenship-based taxation keeps worldwide liability attached to nationality even after the citizen settles abroad.
| Citizenship-Based Taxation | Residence-Based Taxation | |
|---|---|---|
| Connecting factor | Nationality of the individual | Residence under domestic tests such as days or home |
| Effect of moving abroad | Filing and worldwide liability generally continue | Worldwide liability generally ends once residence is lost, subject to local rules |
| How the link ends | Relinquishment of citizenship, possibly with expatriation tax | Ceasing residence, possibly with exit tax in some countries |
Example
Illustrative example: A US citizen works remotely as a freelance developer while living in Country A, which taxes residents on worldwide income. Country A taxes the developer as a resident, and the United States still requires a US return because of citizenship. The developer may exclude part of foreign earned income if the physical presence test of 330 full days abroad in 12 consecutive months, an illustrative IRS reference point, is met, or may claim a foreign tax credit for Country A tax on the same income. Either route generally reduces double taxation, but US filing continues each year, along with any FBAR reporting of foreign accounts. If the developer later renounces citizenship, the expatriation date and the covered expatriate tests determine whether a deemed sale of worldwide assets applies.
Common misconception
Myth: A US citizen who lives abroad and pays tax in another country no longer has to file US tax returns.
Reality: Under citizenship-based taxation, US citizens generally remain subject to US tax on worldwide income and to the same filing rules whether living in the United States or abroad, with exclusions and credits reducing double taxation.
Frequently asked questions
What is citizenship-based taxation?
Citizenship-Based Taxation is a system under which a country taxes citizens on worldwide income wherever they live; the United States applies it to federal income tax, with relief such as the foreign earned income exclusion and foreign tax credit.
Do US citizens living abroad have to pay US taxes?
US citizens living abroad are generally subject to US tax on worldwide income and to the same filing rules as at home; exclusions and foreign tax credits often reduce, but do not automatically eliminate, the US liability.
How does citizenship-based taxation differ from residence-based taxation?
Citizenship-Based Taxation ties worldwide liability to nationality, so moving abroad does not end it, whereas residence-based taxation ties worldwide liability to residence tests, so losing residence generally ends it, subject to local rules.
Related terms
- Worldwide Taxation — Scope of income covered, often confused with CBT
- Territorial Tax System — Contrasting system taxing only domestic-source income
- Foreign Earned Income Exclusion — Main US relief for citizens working abroad
- Accidental American — Citizens abroad caught by CBT unknowingly
Related guides
- US expat tax reform debate — Debate on moving US expats to residence-based taxation
- Global tax reform and US digital nomads — US nomad obligations under worldwide taxation
Sources
- IRS: US citizens and resident aliens abroad
- IRS: Foreign earned income exclusion
- IRS: Instructions for Form 8854
- IRS: Expatriation tax
Last verified: 2026-10-08. This entry is general information, not tax or legal advice; rules vary by country and change over time.
