|Legal status of persons|
Multiple citizenship is a status in which a person is concurrently regarded as a citizen under the laws of more than one state. Multiple citizenships exist because different countries use different, and not necessarily mutually exclusive, citizenship requirements. Colloquial speech refers to people "holding" multiple citizenship but technically each nation makes a claim that this person be considered its national. For this reason, it is possible for a person to be a citizen of one or more countries, or even no country.
Citizenship of multiple countries 
Individual countries follow their own rationales in establishing their criteria for citizenship. Each country has different requirements and policies on both acquiring its citizenship and holding other citizenships concurrently. These laws sometimes create situations where someone may acquire other citizenships without rendering the original citizenship invalid, or where someone may satisfy the citizenship requirements of more than one country simultaneously through no action of his or her own (e.g. at birth). This would allow the individual to hold two or more nationalities. Here are common reasons to bestow citizenship:
- At least one parent is a citizen (jus sanguinis).
- The person was born on the country's territory (jus soli)
- The person marries a citizen (jure matrimonii).
- The person becomes naturalized.
- The person was adopted from another country as a minor and at least one adoptive parent is a citizen.
- The person makes a substantial monetary investment: Austria, Cyprus, Dominica and St. Kitts & Nevis.
Once a country bestows citizenship, it may or may not consider a voluntary renunciation of that citizenship to be valid. In the case of naturalization, some countries require applicants for naturalization to renounce their former citizenship. However, this renunciation may not be recognized by the renounced country. Technically, the person in question may still possess both citizenships.
For example, United States Chief Justice John Rutledge ruled "a man may, at the same time, enjoy the rights of citizenship under two governments," but the US requires applicants for naturalization to swear to an oath renouncing all prior "allegiance and fidelity" to any other nation or sovereignty as part of the naturalization ceremony. In the case of a British citizen, however, the UK honors renunciation of citizenship only if done with competent UK authorities. Consequently, British citizens naturalized in the US remain British citizens in the eyes of the British government even after they renounce British allegiance to the satisfaction of U.S. authorities.
The Republic of Ireland frames its citizenship laws as relating to "the island of Ireland", thereby extending them to Northern Ireland, which is part of the United Kingdom. Therefore, anyone born in Northern Ireland who meets the requirements for being an Irish citizen through birth on the island of Ireland (or a child born outside of Ireland but with a qualifying parent) may exercise an entitlement to Irish citizenship by acting in such a way that only an Irish citizen is entitled to do (such as applying for an Irish passport). Conversely, that such a person has not acted in this way does not necessarily mean that they are not entitled to be an Irish citizen. See Irish nationality law and British nationality law. People born in Northern Ireland are British citizens on the same basis as people born elsewhere in the United Kingdom. People born in Northern Ireland may choose to hold a British passport, an Irish passport, or both.
Multiple citizenship avoided 
Some countries consider multiple citizenship undesirable and take measures to avoid it. Since a country only has control over who has its citizenship, but has no control over who has any other country's citizenship, the only way for a country to avoid multiple citizenship is to deny its citizenship to people in cases when they would have another citizenship. This may take the following forms:
- Automatic loss of citizenship if another citizenship is acquired voluntarily (such as Azerbaijan, China, Czech Republic, Denmark, India, Indonesia, Japan, Kazakhstan,, Nepal, the Netherlands, Norway). In the case of the Czech Republic, two specific exceptions apply: those who acquired other citizenship after being illegally deprived of citizenship by the Communist regime of 1948–1990, or whose Slovak citizenship as of September 31, 1992, caused automatic loss of Czech citizenship upon the partition of Czechoslovakia, may apply for restoration of Czech citizenship without losing another. However, in October 2012 the Czech Ministry of the Interior presented a draft of a revision of the Citizenship Act that, if passed by the Parliament, will inter alia (besides the existing options: by birth, through marriage, by means of restoration of one's citizenship in certain cases and by virtue of a statutory exception granted by the state authorities ) provide a new cause of obtaining dual citizenship on the basis of a voluntary acceptance of a foreign citizenship while retaining the Czech one. Thus, the Czech Republic would become one of those few EU member states (for example United Kingdom or Hungary) fully supporting dual citizenship regime. Saudi Arabian citizenship may be withdrawn if a Saudi citizen obtains a foreign citizenship without the permission of the Prime Minister.
- Possible (but not automatic) loss of citizenship if another citizenship is acquired voluntarily (such as Singapore, Malaysia, South Africa).
- Possible (but not automatic) loss of citizenship if people with multiple citizenships do not renounce their other citizenships after reaching the age of majority or within a certain period of time after obtaining multiple citizenships (such as Japan and Montenegro. In Montenegro loss is automatic with some exceptions.)
- Denying automatic citizenship from birth if the child may acquire another citizenship automatically at birth.
- Requiring an applicant for naturalization to apply to renounce his/her existing citizenship(s), and provide proof from those countries that they have renounced citizenship, as a condition of naturalization.
Some countries have more complex rules on dual and multiple citizenship. For example,
- Germany and Austria usually do not allow dual citizenship except for persons who obtain more than one citizenship at the time of birth. Germans and Austrians can apply for a permit to keep their citizenship (Beibehaltungsgenehmigung) before taking a second one (for example, both Austria and the U.S. consider Arnold Schwarzenegger a citizen). In general however, any Austrian who takes up a second citizenship will automatically lose Austrian citizenship.
- Acquisition of the nationality of Latin American countries, Andorra, the Philippines, Equatorial Guinea or Portugal is not sufficient to cause the loss of Spanish nationality by birth. Spain has dual citizenship treaties with Argentina, Bolivia, Chile, Colombia[not in citation given], Costa Rica, the Dominican Republic, Ecuador, Honduras, Guatemala, Nicaragua, Paraguay, and Peru; Spaniards residing in these countries do not lose their rights as Spaniards if they adopt that nationality. For all other countries, Spanish citizenship is lost three years after the acquisition of the foreign citizenship unless the individual declares officially their will to retain Spanish citizenship (Spanish Nationality Law). Upon request Spain has allowed persons from Puerto Rico to acquire Spanish citizenship.
Overseas citizenship of India 
The Constitution of India does not permit dual citizenship or dual nationality, except for minors where the second nationality was involuntarily acquired. Indian authorities interpreted this to mean a person cannot have another country's passport while simultaneously holding an Indian one, even for a child claimed by another country as its citizen, who may be required by the laws of this country to use the corresponding passports for foreign travel (such as a child born in the United States to Indian parents). Indian courts have given the executive branch wide discretion over this matter.
In 2005, India amended the 1955 Citizenship Act to introduce a form of overseas citizenship, which stops just short of full dual citizenship and is, in all aspects, like Permanent Residency. Such overseas citizens are exempt from the rule forbidding dual citizenship; they may not vote, run for office, join the army, or take up government posts, though these evolving principles are subject to revolving political discretions[clarification needed] if you are born in India with birthrights. Moreover, people who have acquired citizenship in Pakistan or Bangladesh are not eligible for Overseas Citizenship.
Multiple citizenship "not recognized" 
Saying that a country "does not recognize" multiple citizenship is a confusing and ambiguous term. Often, it is simply a restatement of the Master Nationality Rule, which means that a country treats a multiple-citizen, one of whose citizenships is that country's, no differently than a sole-citizen of that country. In other words, the country "does not recognize" this multiple-citizen person has multiple citizenships, for the purposes of the country's laws, even though the person may actually be regarded as a citizen by other countries according to their laws. In particular, this may mean that if you're a citizen of that country, you cannot use another country's passport or citizenship documents to enter or leave the country.
Multiple citizenship encouraged 
Some countries consider multiple citizenship desirable as it increases opportunities for their citizens to compete globally, and/or have taken active steps towards permitting multiple citizenship in recent years (such as Switzerland since 1 January 1992 and Australia since 4 April 2002).
Multiple citizenship required 
Subnational citizenship 
- Under the Fourteenth Amendment to the United States Constitution, all persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they are deemed to reside. Certain rights accrue as an incident of state citizenship and access to federal courts can sometimes be determined on State citizenship.
- Switzerland has a three tier system of citizenship - Confederation, canton and commune (municipality).
- Although considered part of the United Kingdom for British nationality purposes, the Crown Dependencies of Jersey, Guernsey and the Isle of Man have local legislation restricting certain employment and housing rights to those with "local status". Although the British citizenship of people from these islands gives them full citizenship rights when in the United Kingdom, it does not give them the rights that British citizenship generally confers when in other parts of the European Union (for example, the right to reside and/or work).
- The Australian territory of Norfolk Island has immigration laws that restrict residence in the territory to those with "local status". Most Norfolk Islanders are Australian citizens.
- The statuses of permanent residency of Hong Kong and Macau, each a Special Administrative Region of the People's Republic of China, are overlaid on Chinese nationality as stipulated in their respective basic laws. Those who concurrently have Chinese nationality and permanent residency in either SAR are entitled a Chinese passport issued by that SAR, which affords them more visa waivers. Laws may confer specific rights to certain persons by virtue of being a Chinese national (such as the right to transmit nationality by birth), a resident (permanent or all) of the region (e.g. right to vote in local elections), or a combination of both (such as the right to hold public office above a certain level). It is now possible to be a permanent resident of both Special Administrative Regions.
- People from Åland have joint regional (Åland) and national (Finnish) citizenship. People with Ålandic citizenship (hembygdsrätt) have the right to buy property and set up a business on Åland, but Finns without regional citizenship cannot. Finns can get Ålandic citizenship after living on the islands for five years, and Ålanders lose their regional citizenship after living on the Finnish mainland for five years.
- The government of Puerto Rico began issuing Puerto Rican citizenship certificates in September 2007 after Juan Mari Brás, a lifelong supporter of independence, won a successful court victory that validated his claim that Puerto Rican citizenship was valid and can be claimed by anyone born on the island or with at least one parent who was born there.
- In Bosnia and Herzegovina, citizens hold also citizenship of their respective entity which is generally the Entity of their residence. It can be either citizenship of Republika Srpska or of the Federation of Bosnia and Herzegovina. One cannot hold both entity citizenships simultaneously.
- Following the federalization of Czechoslovakia in 1968, Czechoslovak citizens also possessed an internal citizenship of either the Czech or Slovak Republic. Upon the nation's peaceful dissolution in 1993, this was used to determine whether they ought to receive Czech or Slovak citizenship.
- Before the break-up of Yugoslavia in 1991, Yugoslav citizens possessed an internal citizenship of their own republic (Serbia, Croatia, Slovenia etc.) as well as Yugoslav citizenship. In Serbia and Montenegro, this system was in effect until 2006.
Supra-national citizenship 
- In European Union law there is the concept of EU citizenship which flows from citizenship of a member state. A citizen of an EU country is free to live and to work in another EU country for an unlimited period of time, but member states may reserve the right to vote in national elections, stand for national election, become a public servant in highly sensitive ministries (Defence for example), etc. only for their citizens. An EU state may place restrictions on the free movement rights of citizens of newly admitted states for several years, such provisions remain in force mostly for nationals of Bulgaria and Romania (no later than 2014 but 2016 for Switzerland); in the past, and to a lesser extent, such provisions also affected Estonia, Latvia, Lithuania, Poland, the Czech Republic, Slovakia, Hungary and Slovenia.
- The Commonwealth of Nations has a Commonwealth citizenship for the citizens of its members. Some member states (such as the United Kingdom) allow non-nationals who are Commonwealth citizens to vote and stand for election while resident there. Others make little or no distinction between citizens of other Commonwealth nations and citizens of non-Commonwealth nations.
- Commonwealth of Independent States nations (the republics of the former Soviet Union) are often eligible for fast track processing to citizenships of other CIS countries, with varying degrees of recognition/tolerance of dual citizenship among the states.
Potential issues 
National cohesiveness 
The rise in tension between mainstream and migrant communities is cited as evidence of the need to maintain a strong national identity and culture. They assert that the fact that a second citizenship can be obtained without giving anything up (such as the loss of public benefits, welfare, healthcare, retirement funds, and job opportunities in the country of origin in exchange for citizenship in a new country) both trivializes what it means to be a citizen and nullifies the consequential, transformational, and psychological change that occurs in an individual when they go through the naturalization process.
In effect, this approach argues, the self-centered taking of an additional citizenship contradicts what it means to be a citizen in that it becomes a convenient and painless means of attaining improved economic opportunity without any real consequences and can just as easily be discarded when it is no longer beneficial. Proponents argue that dual citizenship can actually encourage political activity providing an avenue for immigrants who are unwilling to forsake their country of origin either out of loyalty or due to a feeling of separation from the mainstream society because of language, culture, religion, or ethnicity.
A 2007 academic study concluded that dual citizens had a negative effect on the assimilation and political connectedness of first-generation Latino immigrants to the United States:
- 32% less likely to be fluent in English
- 18% less likely to identify as "American"
- 19% less likely to consider the US as their homeland
- 18% less likely to express high levels of civic duty
- 9% less likely to register to vote
- 15% less likely to have ever voted in a national election
The study also noted that although dual nationality is likely to disconnect immigrants from the American political system and impede assimilation, the initial signs suggest that these effects seem to be limited almost exclusively to the first generation (although it is mentioned that a full assessment of dual nationality beyond the first generation is not possible with present data).
Concern over the effect of multiple citizenship on national cohesiveness is generally more acute in the United States. The reason for this is twofold:
- The United States is a "civic" nation and not an "ethnic" nation. American citizenship is not based on belonging to a particular ethnicity, but on political loyalty to American democracy and values. Regimes based on ethnicity, which support the doctrine of perpetual allegiance as one is always a member of the ethnic nation, are not concerned with assimilating non-ethnics since they can never become true citizens. In contrast, the essence of a civic nation makes it imperative that immigrants assimilate into the greater whole as there is not an "ethnic" cohesiveness uniting the populace.
- The United States is an immigrant nation. It has prospered due to its immigration policy of taking in and absorbing a very diverse stock of immigrants. As immigration is primarily directed at family reunification and/or refugee status rather than education and job skills, the pool of candidates tends to be poorer, less educated, and consistently from less stable countries (either non-democracies or fragile ones) with less familiarity or understanding of American values, making their assimilation more difficult and important.
The degree of angst over the effects of dual citizenship seemingly corresponds to a country's model for managing immigration and ethnic diversity:
- The differential exclusionary model, which accepts immigrants as temporary "guestworkers" but is highly restrictive with regard to other forms of immigration and to naturalisation of immigrants. Japan, China, Taiwan, and the countries of the Middle East tend to follow this approach.
- The assimilationist model, which accepts that immigrants obtain citizenship, but on the condition that they give up some or all cultural, linguistic, or social characteristics that differ from those of the majority population. The United States is the primary example of this model and given its massive immigration tradition and increasingly diverse population, is very sensitive to matters regarding integration (see Immigration to the United States).
- The multicultural model, which grants immigrants access to citizenship and to equal rights without demanding that they give up cultural, linguistic, and/or intermarriage restrictions or otherwise pressure them to integrate or inter-mix with the mainstream population. Canada, Australia, and many countries in Europe have historically taken this approach, but there is some evidence that Europe is moving toward the assimilationist model (see Immigration to Europe).
Appearance of foreign allegiance 
||The examples and perspective in this section deal primarily with the United States and do not represent a worldwide view of the subject. (June 2009)|
People with multiple citizenship may be viewed as having dual loyalty, having the potential to act contrary to a government's interests, and this may lead to difficulties in acquiring government employment where security clearance may be required.
In the United States, dual citizenship is associated with two categories of security concerns: foreign influence and foreign preference. Contrary to common misconceptions, dual citizenship in itself is not the major problem in obtaining or retaining security clearance in the United States. As a matter of fact, if a security clearance applicant's dual citizenship is "based solely on parents' citizenship or birth in a foreign country", that can be a mitigating condition. However, taking advantage of the entitlements of a non-US citizenship can cause problems. For example, possession and/or use of a foreign passport is a condition disqualifying one from security clearance and "is not mitigated by reasons of personal convenience, safety, requirements of foreign law, or the identity of the foreign country" as is explicitly clarified in a Department of Defense policy memorandum which defines a guideline requiring that "any clearance be denied or revoked unless the applicant surrenders the foreign passport or obtains official permission for its use from the appropriate agency of the United States Government".
This guideline has been followed in administrative rulings by the United States Department of Defense (DoD) Defense Office of Hearings and Appeals (DOHA) office of Industrial Security Clearance Review (ISCR), which decides cases involving security clearances for Contractor personnel doing classified work for all DoD components. In one such case, an administrative judge ruled that it is not clearly consistent with US national interest to grant a request for a security clearance to an applicant who was a dual national of the US and Ireland, despite the fact that it has with good relations with the US.
In Israel, certain military units, including most recently the Israeli Navy's submarine fleet, as well as posts requiring high security clearances, require candidates to renounce any other citizenship before joining, though the number of units making such demands has declined. In many combat units, candidates are required to declare but not renounce any foreign citizenship.
On the other hand, Israel may view some dual citizens as desirable candidates for its security services due to their ability to legitimately enter neighbouring states which are closed to Israeli passport holders. The related case of Ben Zygier has caused debate about dual citizenship in Australia.
Multiple citizenship among politicians 
This perception of dual loyalty can apply even when the job in question does not require security clearance. In the United States, dual citizenship is common among politicians or government employees. For example, Arnold Schwarzenegger retained his Austrian citizenship during his service as a Governor of California. In 1999, the U.S. Attorney General's office issued an official opinion that a statutory provision that required the Justice Department not to employ a non-"citizen of the United States" did not bar it from employing dual citizens.
In 2006, Boris Johnson (at the time a Member of the British Parliament and afterward Mayor of London) renounced the US citizenship he had acquired by being born in New York. He declared: "After 42 happy years I am getting a divorce from America. It is not just that I no longer want an American passport. In fact, what I want is the right not to have an American passport." His renunciation was prompted by US laws that require a US citizen entering the United States to use a US passport, rather than any other passport.
A small controversy arose in 2005 when Michaëlle Jean was appointed the Governor General of Canada (official representative of the Queen). Although Jean no longer holds citizenship in her native Haiti, her marriage to French-born filmmaker Jean-Daniel Lafond allowed her to obtain French citizenship several years before her appointment. Article 23-8 of the French civil code allows the French government to withdraw the French nationality from French citizens holding government or military positions in other countries and Jean's appointment made her both de facto head of state and commander-in-chief of the Canadian forces. The French embassy released a statement that this law would not be enforced because the Governor General is essentially a ceremonial figurehead. Nevertheless, Jean renounced her French citizenship two days before taking up office to end the controversy about it.
However, former Canadian Prime Minister John Turner was born in the United Kingdom and still retains his dual citizenship. Stéphane Dion, former head of the Liberal Party of Canada and the previous leader of the official opposition, holds dual citizenship with France as a result of his mother's nationality; Dion nonetheless indicated a willingness to renounce French citizenship if a significant number of Canadians viewed it negatively. Thomas Mulcair, Leader of the NDP and opposition leader of the Canadian House of Commons also holds dual citizenship with France.
The Constitution of Australia, in Section 44(i), explicitly forbids people who hold foreign citizenship from sitting in the parliament of Australia. A court case (see Sue v Hill) determined that the UK is a foreign power for purposes of this section of the constitution, despite Australia holding a common nationality with it at the time that the Constitution was written, and that Senator-elect Heather Hill had not been duly elected to the national parliament because at the time of her election she was a subject or citizen of a foreign power. (This restriction does not apply to members of the state parliaments, where regulations vary by state.)
In New Zealand, controversy arose in 2003 when Labour MP Harry Duynhoven applied to renew his citizenship of the Netherlands. Duynhoven, the New Zealand-born son of a Dutch-born father, had possessed dual citizenship from birth but had temporarily lost his Dutch citizenship due to a 1995 change in Dutch law regarding non-residents. While New Zealand's Electoral Act allowed candidates with dual citizenship to be elected as MPs, Section 55 of the Act stated that an MP who applied for citizenship of a foreign power after taking office would forfeit his/her seat. This was regarded by many as a technicality, however; and Duynhoven, with his large electoral majority, was almost certain to re-enter Parliament in the event of a by-election. As such, the Labour Government retrospectively amended the Act, thus enabling Duynhoven to retain his seat. The amendment, nicknamed "Harry's Law", was passed by a majority of 61 votes to 56. The revised Act allows exceptions to Section 55 on the grounds of an MP's country/place of birth, descent, or renewing a foreign passport issued before the MP took office.
Both the current[update] Estonian president Toomas Hendrik Ilves and the former Lithuanian president Valdas Adamkus had been naturalized US citizens prior to assuming their offices. Both have renounced their U.S. citizenships: Ilves in 1993 and Adamkus in 1998. This was necessary because neither individual's new country permits retention of a former citizenship. Adamkus was a high-ranking official in the Environmental Protection Agency, a federal government department, during his time in the United States.
In some cases, multiple citizenship can create additional tax liability. Most countries that impose tax normally base tax liability on source and/or residency. Only two countries base taxation on citizenship: the United States and Eritrea.
- Residency: a country may tax the income of anyone who lives there, regardless of citizenship or whether the income was earned in that country or abroad;
- Source: a country may tax any income generated there, regardless of whether the earner is a citizen, resident, or non-resident; or
- Citizenship: a country may tax the worldwide income of its citizens, regardless of whether they reside in that country or whether the income was sourced there.
A few countries, such as the Philippines, consider citizenship to a limited extent. Only U.S. expatriates (who have not renounced citizenship) are subject to tax on all of their worldwide income, although U.S. law provides measures to reduce or eliminate double taxation issues for some expatriates. It has been reported that some U.S. expatriates have renounced U.S. citizenship in order to avoid this tax burden.
A person with multiple citizenship may have a tax liability to his country of residence and also to one or more of his countries of citizenship; or worse, if unaware that one of his citizenships created a tax liability, that country may consider the person to be a tax evader. Many countries and territories have contracted tax treaties or agreements for avoiding double taxation. Still, there are cases in which a person with multiple citizenship will owe tax solely on the basis of holding one of those citizenships.
For example, consider a person who holds both Australian and United States citizenship, lives and works in Australia. He would be subject to Australian taxation, because Australia taxes its residents, and he would be subject to US taxation because he holds US citizenship. In general, he would be allowed to subtract the Australian income tax he paid from the US tax that would be due. Plus, the US will allow some parts of foreign income to be exempt from taxation; for instance, in 2006 the foreign earned income exclusion allowed up to US$82,400 of foreign salaried income to be exempt from income tax. This exemption, plus the credit for foreign taxes paid mentioned above, often results in no US taxes being owed, although a US tax return would still have to be filed. In instances where the Australian tax was less than the US tax, and if there was income that could not be exempted from US tax, the US would expect any tax due to be paid.
The United States Internal Revenue Service has excluded some regulations such as Alternative Minimum Tax (AMT) from tax treaties that protect double taxation. In its current format even if US citizens are paying income taxes at a rate of 56%, far above the maximum US marginal tax rate, the citizen can be subject to US taxes because the calculation of the Alternative Minimum Tax does not allow full deduction for taxes paid to a foreign country. Other regulations such as the post date of foreign mailed tax returns are not recognized and can result in penalties for late filing if they arrive at the IRS later than the filing date.
However, the filing date for overseas citizens has a two month automatic extension to the 15th of June.
"If you are a U.S. citizen or resident alien residing overseas, or are in the military on duty outside the U.S., on the regular due date of your return, you are allowed an automatic 2-month extension to file your return and pay any amount due without requesting an extension. For a calendar year return, the automatic 2-month extension is to June 15.
If you are unable to file your return by the automatic 2-month extension date, you can request an additional extension to October 15 by filing Form 4868 before the automatic 2-month extension date. However, any tax due payments made after June 15 will be subject to both interest charges and failure to pay penalties." (IRS, 2012)
Issues with international travel 
Many countries, even those that permit multiple citizenship, do not explicitly recognise multiple citizenship under their laws: individuals are treated either as citizens of that country or not, and their citizenship with respect to other countries is considered to have no bearing. This can mean (in Iran, Mexico, many Arab countries, and former Soviet republics) that consular officials abroad may not have access to their citizens if they also hold local citizenship. Some countries provide access for consular officials as a matter of courtesy, but do not accept any obligation to do so under international consular agreements. The right of countries to act in this fashion is protected via the Master Nationality Rule.
Multiple citizens who travel to a country that claims them as a citizen may be required to enter or leave the country on that country's passport. For example, a United States Department of State web page on dual nationality contains the information that most U.S. citizens, including dual nationals, must use a U.S. passport to enter and leave the United States. Also, terms of the South African Citizenship Act, it is an offence for someone aged at least 18 with South African citizenship and another citizenship to enter or depart the Republic of South Africa by using of the passport of another country. They may also be required, before leaving the country, to fulfill requirements ordinarily required of its resident citizens, including compulsory military service or exit permits.
See also 
- Canadians of convenience
- History of citizenship
- Nationality law
- Talbot v. Janson
- "Civil Code of Iran (last amended 1985)". United Nations High Commissioner for Refugees. Retrieved 2007-06-24. "Article 976 - The following persons are considered to be Iranian subjects: [...] (6) Every woman of foreign nationality who marries an Iranian husband."
- For example, this is the case in the United States. Citizenship is automatic when the adoption becomes final, with no need for the naturalization process. See "Information about the Child Citizenship Act". Intercountry Adoption. Office of Children's Issues, United States Department of State. Retrieved 2011-03-12.
- http://www.henleyglobal.com/countries/austria/citizenship/ Citizenship in Austria
- Citizenship by Investment, tayloredway.com
- Talbot v. Janson, 3 U.S. 133 (1795)  .
- A Guide to naturalization, US Citizenship and Immigration Services. (Responsibilities, page 2).
- How do I give up British citizenship or another form of British nationality?, UK Border Agency.
- Azerbaijani law on citizenship
- Undang-Undang Republik Indonesia Nomor 12 Tahun 2006
- Article 11, The Nationality Law, Ministry of Justice of Japan.
- the Citizenship Act Revision proposed by the Czech authorities
- Czech Ministry of the Interior - information about dual citizenship, automatic translation by Google Translate
- "1954 Saudi Arabian Citizenship System". Articles 11 and 13. Retrieved 2012-02-05.
- "South African Department of Home Affairs: Citizenship". Retrieved 11 August 2011.
- "The Choice Of Nationality". Japan Ministry Of Justice. Retrieved 10 June 2010.
- Montenegro: Dual citizenship forbidden, but this article is about one known exception.
- Dual Citizenship, Austrian Embassy, Ottawa, Canada.
- Dual Citizenship, German Embassy, Ottawa, Canada.
- Spanish Civil Code, Art. 24.
- European Citizenship Laws: DUAL SPANISH CITIZENSHIP Application, immigrationcitizenship.eu, 2009.
- Spanish Civil Code, Art. 25.
- "Puerto Rican stars granted Spanish citizenship". Puerto Rico Daily Sun. November 5, 2011.
- USA TODAY: "Oscar winner Benicio del Toro, singer Ricky Martin become Spanish citizens" By Maria Puente November 04, 2011
- Overseas Citizenship of India Scheme
- "India Dual Citizenship". immihelp.com. Retrieved 2007-08-29.
- "Swiss Citizenship". Swiss Government.
- "Introduction to Dual Citizenship". Australian Government.
- Admission requirements Official Vatican web page, Roman Curia, Swiss Guards, retrieved August 7, 2006
- "Vatican citizenship". Holy See Press Office. Retrieved 2006-12-03.
- "Åland in Brief — Right of Domicile". det offentliga Åland. Archived from the original on 2007-08-22. Retrieved 2007-09-26.
- "Right of domicile in Åland". Parliament of Åland. Archived from the original on 2007-07-04. Retrieved 2007-09-26.
- "Puerto Rican independence activist gets island citizenship ID". signonsandiego.com. Retrieved 2007-09-26.
- Džankić, Jelena (Autumn 2010), Transformations of Citizenship in Montenegro: a context-generated evolution of citizenship policies, CITSEE Working Paper Series, University of Edinburgh, retrieved 2011-05-12
- Staton, Jeffrey K. (Florida State University); Jackson, Robert A. (Florida State University); Camache, Damaryas (University of Illinois): "Dual Nationality Among Latinos: What are the Implications for Political Connectedness."
- Renshon, Stanley; "Dual Citizenship and American National Identity" Center for Immigration Studies 2001.
- "The Naturalization Oath Ceremony, and What It Means To Be a U.S. Citizen"
- Brown, Gregg "Political Bigamy?: Dual Citizenship in Australia's Migrant Communities"
- Faist, Thomas; Gerdes, Jurgen (Bielefeld University) "Dual Citizenship in an Age of Mobility" 2008.
- Staton, Jeffrey K. (Florida State University); Jackson, Robert A. (Florida State University); Camache, Damaryas (University of Illinois): "Costly Citizenship, Dual Nationality Institutions, Naturalization, and Political Connectedness"
- 2006 Dual Citizenship, Birthright Citizenship, and the meaning of Sovereignty Hearing before the Subcommittee on Immigration, Border Security, and Claims of the Committee on the Judiciary. 109th Congress, First Session, September 29, 2005, Serial No. 109–63.
- Public Policy Institute of California: "Immigrants and Education" June 2008.
- Globalisation, Journal of Ethnic and Migration Studies: "Multiculturalism and Individualism: the Swedish Debate on Dual Citizenship" July 1, 2002.
- "Security Clearance Guidelines: Foreign Preference". military.about.com. Retrieved 2007-05-15.
- Arthur L. Money (16 August 2000). "Guidance to DoD Central Adjudication Facilities (CAF) Clarifying the Application of the Foreign preference Adjucitative Guideline" (pdf). Retrieved 2007-05-15. (the "Money Memorandum")
- ISCR Case No. 02-21102
- Nadin, Mitchell. "Ben Zygier case to spark dual passport review". The Australian. Retrieved 28 February 2013.
- BBC News (January 22, 2005). "Schwarzenegger 'damages Austria'". news.bbc.co.uk. Retrieved 2007-10-11.
- Treasury and General Government Appropriations Act, 1999, Pub. L. No. 105-277, 112 Stat. 2681-480, 2681-513-14, § 606
- Eligibility of a Dual United States Citizen for a Paid Position with the Department of Justice, Opinions of the Attorney General, August 26, 1999 (Beth Nolan, Deputy Assistant Attorney General, Office of Legal Counsel)
- Giving Up US Citizenship: Is it Right for You?
- Express.co.uk - Home of the Daily and Sunday Express | UK News :: Furious Boris renounces his US citizenship
- Perd la nationalité française le Français qui, occupant un emploi dans une armée ou un service public étranger ou dans une organisation internationale dont la France ne fait pas partie ou plus généralement leur apportant son concours, n'a pas résigné son emploi ou cessé son concours nonobstant l'injonction qui lui en aura été faite par le Gouvernement.
L'intéressé sera, par décret en Conseil d'Etat, déclaré avoir perdu la nationalité française si, dans le délai fixé par l'injonction, délai qui ne peut être inférieur à quinze jours et supérieur à deux mois, il n'a pas mis fin à son activité.
Lorsque l'avis du Conseil d'Etat est défavorable, la mesure prévue à l'alinéa précédent ne peut être prise que par décret en conseil des ministres.
Retrieved from LegiFrance December 12, 2008 with English translation at )
- CBC News: New governor general to give up French citizenship; September 25, 2005
- CBC News (December 8, 2006). "Dion would sacrifice French citizenship to become PM". CBC.ca. Retrieved 2006-12-08.
- "An Act to constitute the Commonwealth of Australia". Parliament of Australia. July 9, 1900.
- "Sue v Hill (1999) HCA 30; 199 CLR 462; 163 ALR 648; 73 ALJR 1016 (23 June 1999)". High Court of Australia. June 23, 1999. Retrieved 2008-05-22.
- New Zealand Herald (24 July 2003). "Minister's Dutch ties put House in a bind". Unknown parameter
- "New Zealand Electoral Act 1993, Section 55". Retrieved 16 July 2011.
- New Zealand Herald (28 July 2003). "Parties brace to fight 'Harry's law'". Retrieved 16 July 2011.
- New Zealand Herald (8 August 2003). "Labour in laager on passports". Retrieved 16 July 2011.
- "New Zealand Electoral Act 1993, Section 55AA". Retrieved 16 July 2011.
- [unreliable source?]
- Republic Act No. 8424: The National Internal Revenue Code of the Philippines. ChanRobles Law Library. "SEC. 23. General Principles of Income Taxation in the Philippines. - Except when otherwise provided in this Code: (A) A citizen of the Philippines residing therein is taxable on all income derived from sources within and without the Philippines; (B) A nonresident citizen is taxable only on income derived from sources within the Philippines; [...] (D) An alien individual, whether a resident or not of the Philippines, is taxable only on income derived from sources within the Philippines;"".
- Doreen Carvajal (December 17, 2006). "Americans abroad are giving up citizenship for lower taxes". International Herald Tribune.
- Helena Bachmann (April 20, 2010). "Why More U.S. Expatriates Are Turning In Their Passports". time.com.
- IRS Foreign Earned Income Exclusion
- US Internal Revenue Service: U.S. Citizens and Resident Aliens Abroad
- "travel report — Iran". Department of foreign Arrairs and International Trade, Canada. Archived from the original on 2007-06-11. Retrieved 2007-09-26.
- "Mexican Nationality Law, Article XIV". Secretariat of Foreign Affairs.
- "US State Department Services Dual Nationality". U.S. Department of State.
- Spanish Civil Code, Ministry of Justice of Spain
Further reading 
- Randall Hansen, Patrick Weil, ed. (January 2002). Dual Nationality, Social Rights and Federal Citizenship in the U. S. and Europe: The Reinvention of Citizenship. Berghahn Books. ISBN 1-57181-804-9.
- Thomas Faist, ed. (August 2007). Dual Citizenship in Europe: From Nationhood to Societal Integration. Aldershot, UK: Ashgate. ISBN 978-0-7546-4914-4.
- Thomas Faist, Peter Kivisto, ed. (November 2007). Dual Citizenship in Global Perspective: From Unitary to Multiple Citizenship. Houndmills, UK: Palgrave Macmillan. ISBN 978-0-230-00654-6.
- Thomas Faist and Jürgen Gerdes (2008). "Dual Citizenship in an Age of Mobility" (PDF). Transatlantic Council on Migration (MPI). Retrieved 2012-04-26.
- Federal Investigative Services Division of the U.S. Office of Personnel Management (2001). "Citizenship Laws of the World: A Directory" (PDF). Retrieved 2008-01-28.
- The Hague 1930 Convention
- Convention n°8 on the exchange of information concerning acquisition of nationality, 1964
- Council of Europe
- Convention on the Reduction of Cases of Multiple Nationality and on Military Obligations in Cases of Multiple Nationality, 1963
- European Convention on Nationality, 1997