Dual citizenship

What Is Dual Citizenship

Dual citizenship is the legal status of a person who is simultaneously a citizen of two states on the basis of an interstate agreement in force between those states. In the strict legal sense, the term applies specifically to a situation in which the two states have concluded a treaty governing the reciprocal rights and obligations of their citizens.

The operative word here is "agreement." Without a valid interstate agreement on dual citizenship, the status is more accurately described as "second" or "multiple" citizenship (see the next section). The treaty determines which state is treated as the "primary" one for purposes of tax residency, military service, diplomatic protection, social security, and other public-law relationships.

This distinction is drawn directly in Russian legal doctrine and in the Federal Law "On Citizenship of the Russian Federation": dual citizenship arises for a Russian citizen only where Russia has a relevant international treaty in force. In the absence of such a treaty, the acquisition of foreign citizenship produces the status of two citizenships (multiple citizenship), regulated differently: each state, under its own internal law, treats the person as its own citizen.

Dual vs. Second (Multiple) Citizenship

Although in everyday usage "dual" and "second/multiple" citizenship are treated as synonyms, they are legally distinct statuses with different legal consequences.

• Dual citizenship — there is a treaty between the two states. The treaty resolves conflicts (which country is "primary" for taxes, military service, pensions, consular protection abroad).
• Second (multiple) citizenship — there are no treaties. The person in fact holds two or more passports; each state treats him as its own citizen under its internal law and does not recognise the other citizenship.

A classic example of "dual citizenship" in the strict sense is the Agreement between the Russian Federation and the Republic of Tajikistan (a matter of public record). It directly regulates questions of military service, social and pension entitlements, tying them to the state of the dual citizen's permanent residence.

An example of "second citizenship" is a Russian who obtains an EU passport for investment or by descent. There is no dual-citizenship treaty between Russia and that country; both states, under their internal law, treat the person as their own citizen, and conflicts are resolved under the general rules of each country.

Why the terms are confused: in English, the same expression — dual citizenship (or multiple citizenship where there are more than two passports) — covers both statuses. The treaty nuance is largely a post-Soviet doctrinal tradition, unfamiliar to most Western legal systems. In international practice, therefore, "dual citizenship" denotes both strict dual citizenship and ordinary second citizenship.

How Countries Treat Multiple Citizenship

There is no single international standard. Each state independently determines whether it permits its citizens to hold multiple citizenship. Three principal regimes can be identified.

Countries Recognising Multiple Citizenship

Most Western democracies permit multiple citizenship: the United Kingdom, the United States, Canada, Australia, New Zealand, France, Ireland, Portugal, Sweden and many others. The majority of European Union member states allow their citizens to hold a foreign passport. Acquiring foreign citizenship does not entail automatic loss of citizenship in those countries.

Countries Historically Requiring Renunciation

A number of states have long required naturalising foreigners to renounce their previous citizenship. Historically these included Austria, Germany, Japan and China. Practice, however, evolves:

• Germany enacted reform in 2024 that significantly expanded the availability of multiple citizenship — both for naturalising foreigners and for Germans acquiring foreign citizenship.
• Austria generally requires renunciation but permits exceptions (special merit, impossibility of renouncing, the interests of the state).
• Japan, under its Nationality Act, requires a person with dual citizenship to choose one nationality upon reaching majority and, in practice, requires renunciation.
• China, under its 1980 Nationality Law, does not recognise dual citizenship; the acquisition of foreign citizenship may entail loss of Chinese citizenship.
• India does not permit full multiple citizenship (the OCI status — Overseas Citizen of India — is not a citizenship).

Intermediate Regimes

Many countries occupy an intermediate position: they formally permit multiple citizenship but impose restrictions (for example, a ban on holding certain public offices, on employment in the security sector, on owning land in border areas). Russia permits its citizens to hold foreign citizenship (subject to a number of restrictions on public service) but legally recognises the status of dual citizenship only where there is a treaty.

Important caveat: rules change, sometimes retroactively or with a short transitional period. Any information must be verified at the time of decision — ideally in the primary source (the statute, the website of the migration authority) and with the support of a lawyer qualified in the relevant jurisdiction.

What Conflicts Arise with Two Citizenships

Multiple citizenship generates a set of potential conflicts between the legal orders of the two states. A dual-citizenship treaty resolves some of them; without a treaty they are resolved according to the internal law of each country.

Double Taxation and Tax Treaties

The principal conflict is the potential taxation of income by both states. The situation is especially acute where one of the states applies the principle of citizenship-based taxation: in that case it taxes the worldwide income of its citizens regardless of where they live. The classic example is the United States; Eritrea applies a comparable principle.

Most other states tax on the basis of residence (the place of actual residence). To eliminate double taxation, states conclude bilateral tax treaties (under the OECD model). The principal instrument for resolving residency disputes is the so-called tie-breaker test (Article 4 of the OECD Model Convention): a sequential test of criteria (permanent home, centre of vital interests, habitual abode, citizenship) allowing a single state of residency to be determined for treaty purposes.

Citizenship of a country applying citizenship-based taxation is not removed by a simple change of residence — renunciation of citizenship may be accompanied by additional tax checks (such as an exit tax and similar mechanisms).

Military Service

A person holding the citizenship of two states may be called up for military service in both. Dual-citizenship treaties (as in the case of Russia–Tajikistan) resolve the question by reference to the place of permanent residence. Without a treaty, the person risks being required to perform service in both countries. International law (Article 28 of the 1997 European Convention on Nationality) permits states not to treat persons who have performed military service in one of the countries as evading service in the other — but such norms apply only between parties to the relevant conventions and within the scope of their operation.

Diplomatic Protection

When a dual citizen finds himself in a third country, the question of which of his states of citizenship is entitled to diplomatic protection is resolved by international law. Under the leading authority (the Nottebohm case, ICJ, 1955), diplomatic protection requires a genuine and effective link between the person and the state. In practice, consular access to a dual citizen on the territory of one of his states of citizenship is, as a rule, denied to the other state: each country treats him as its own citizen.

Government Service and Access to State Secrets

Multiple citizenship often restricts access to public service, law-enforcement agencies, intelligence services, and positions involving state secrets. In Russia, a number of civil-service positions are restricted for persons with foreign citizenship or a foreign residence permit; similar restrictions exist in many other jurisdictions. This is one of the most common practical conflicts associated with multiple citizenship.

Declaration

A number of states require their citizens to notify the authorities of the acquisition of foreign citizenship or a foreign residence permit. In Russia there is an obligation to file a notification of foreign citizenship or foreign resident status; failure to comply may entail administrative or (in aggravating circumstances) criminal liability. The scope and procedure for declaration depend on the jurisdiction and must be checked for each country of citizenship.

How to Obtain Second Citizenship Without Losing the First

Before considering routes, the key rule: first verify permissibility under the law of both states — the one whose passport is to be acquired and the one whose citizenship must be retained. Loss of the first citizenship often occurs automatically and unnoticed by the person concerned.

Principal routes to second citizenship:

• Investment programmes (Citizenship by Investment, CBI) — grant of citizenship in return for investment in the country's economy (real estate, a state fund, a business). Programmes operate, in particular, in a number of Caribbean states. Each programme has its own requirements as to the amount of investment, due diligence checks, and timing; their terms are regularly revised.
• Citizenship by descent (repatriation, "by roots") — where there are ancestors who were citizens of the relevant state. This is how Israeli citizenship works under the Law of Return, how European countries' programmes for descendants of emigrants operate, and how ethnic-repatriation programmes function.
• Naturalisation by residence — after a certain period of lawful residence on the basis of a residence permit. Many countries reduce the naturalisation period where there are local roots, marriage to a citizen, or special merit.
• Marriage to a citizen — usually shortens the naturalisation period but does not abolish it; in most jurisdictions citizenship is not granted automatically upon marriage.
• Birth on the territory (jus soli) — where applicable (the United States, Canada, many Latin-American countries), a child born on the territory acquires citizenship automatically.

For investment migration, CBI programmes, repatriation, and naturalisation after residence are the most typical routes. Work and employment visas constitute a separate legal regime outside the scope of this article.

Risks and Pitfalls

• Inadvertent loss of the first citizenship. In states that do not permit multiple citizenship (historically Germany, Austria, Japan, China, India and others), the acquisition of a foreign passport may automatically or on demand entail loss of the original citizenship. This is a critical risk to be checked before any step is taken.
• Dual tax residency. With substantial ties to two countries (a home, family, business, time spent), a person may be recognised as a tax resident of both. Resolution through the tie-breaker is not always clear-cut; in disputed cases registration in both countries and information exchange between tax authorities (including automatic exchange under the CRS standard) may be required.
• Military registration of children. Children of dual citizens may become subject to military registration in both countries upon reaching the relevant age, which is particularly difficult where the country of citizenship differs from the country of residence.
• Restrictions on professions. Beyond public service, restrictions may apply to ownership of media, airlines, banks, border-zone land, and licensed professions.
• Penalties for non-declaration. Concealment of information about a foreign citizenship or residence permit is a separate offence in many jurisdictions, often carrying substantial fines or criminal liability.
• Loss of CBI-country citizenship. Investment-citizenship programmes generally contain grounds for deprivation of citizenship (false information on application, criminal prosecution, reputational risk to the state). Deprivation may occur post factum.
• Erosion of CBI programmes. International pressure (changes to visa-free regimes with the EU/UK, changes in passport indices) periodically alters the actual value of the passport obtained.

Who Benefits from Second Citizenship (and Who Risks Losing the First)

Those for Whom It Offers Real Advantages

• Persons for whom global mobility is critical — visa-free access, the possibility of residence in several jurisdictions, insurance against restrictions on the primary passport.
• Families distributing assets and risks between countries, including with a view to children's education and access to markets.
• Persons with lawful grounds for repatriation (roots, ethnicity, the descent of a spouse).
• Entrepreneurs and investors operating in several jurisdictions and needing legal integration with them.

Those at Risk of Losing the First Citizenship or Other Restrictions

• Citizens of states that do not permit multiple citizenship (Austria as a general rule, Japan, China, India and a number of others).
• Persons holding public office or having access to state secrets — restrictions may arise for them even where multiple citizenship is generally permitted.
• Tax residents of states applying citizenship-based taxation — a change or retention of citizenship is accompanied by a complex tax regime.
• Persons for whom loss of the original citizenship is particularly damaging (rights to property, inheritance, family ties, protected status).

How to Verify Permissibility and Where to Start

Steps before any action:

1. Identify the starting position: which country's citizenship the person has and is obliged to retain; what ties he has with each jurisdiction (residency, assets, family).
2. Check the legal regime of multiple citizenship in both countries from primary sources (the nationality law, the website of the migration authority) as of the time of decision — rules change.
3. Assess the tax consequences of each jurisdiction having regard to tax treaties; where necessary, obtain a preliminary calculation from a tax adviser.
4. Check declaration and military-registration obligations.
5. Obtain advice from a lawyer in each of the interested countries before any procedure is started. This is not a formality: an error in classifying the status may cost the original citizenship or entail tax and criminal consequences.

It is particularly important that advice from a specialist in both jurisdictions be obtained before, and not after, action. Many conflicts (such as automatic loss of citizenship) are irreversible.

Frequently Asked Questions

How does dual citizenship differ from second citizenship?

Dual citizenship is a status based on an interstate agreement that regulates which country is "primary" for taxes, military service and so forth. Second (multiple) citizenship is the actual holding of two or more passports without such an agreement; each state treats the person as its own citizen under its internal law.

Does a Russian lose Russian citizenship when acquiring a foreign one?

As a general rule, the acquisition of foreign citizenship does not entail automatic loss of Russian citizenship (Russia permits its citizens to hold foreign citizenship). However, a notification of foreign citizenship or a foreign residence permit must be filed. Legally, Russia recognises the status of "dual citizenship" only where there is an international treaty in force (the treaty with Tajikistan applies).

Must I pay tax in both countries?

It depends on the tax regimes. Where one of the countries applies citizenship-based taxation (for example the United States), it taxes worldwide income regardless of residence; the other country usually taxes on the basis of residency. To avoid double taxation, tax treaties and the tie-breaker test are applied.

What should I do if both countries consider me liable for military service?

The question is regulated by bilateral treaties (where they exist) and by international conventions. Between states party to the 1997 European Convention on Nationality, a person who has performed military service in one of the countries should not be called to service in the other. In the absence of a treaty, the situation is resolved under the internal law of each country and requires individual advice.

Does Russia recognise my second citizenship?

Within the meaning of the Law on Citizenship of the Russian Federation, the holding of foreign citizenship by a Russian citizen does not terminate his Russian citizenship, but on the territory of Russia the person is treated as a Russian citizen (subject to the operation of international treaties). This means that on entry and exit and in public-law relationships within the country the foreign passport is, as a rule, legally immaterial to the Russian authorities.

Can I hold German citizenship and the citizenship of another EU country at the same time?

After the 2024 reform, Germany significantly expanded the availability of multiple citizenship: naturalising foreigners generally retain their previous citizenship, and Germans may acquire foreign citizenship. Nevertheless, the details and transitional provisions require verification at the time of decision.