Multiple citizenship

Multiple citizenship avoided

Some countries consider multiple citizenship undesirable and take measures to avoid it. Since a country has control only 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 Austria,^[17] Azerbaijan,^[18] China (excluding Hong Kong and Macau, which allows Multiple Citizenship in parallel with Chinese Citizenship at the expense of losing Consular Protection from the Country involved in Hong Kong, Macau and China)^[19], India, Indonesia,^[20] Japan,^[21] Kazakhstan,^[22] Nepal,^[23] the Netherlands (unless certain conditions are met), Norway, and Singapore.^[24] Saudi Arabian citizenship may be withdrawn if a Saudi citizen obtains a foreign citizenship without the permission of the Prime Minister (who is also the King).^[25]
• Possible (but not automatic) loss of citizenship if another citizenship is acquired voluntarily, such as South Africa.^[26]
• 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^[27] and Montenegro. In Montenegro loss is automatic with some exceptions.^[28]
• 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.

Involuntary multiple citizenship

Involuntary multiple citizenship can happen in the following ways:

1. If the parents of a child have different citizenships or are multiple citizens themselves, the child may gain multiple citizenship depending on whether and how jus soli and jus sanguinis apply for each citizenship.
2. Some countries (e.g., Canada, the United States of America and many other countries in the Americas) regard all children born there automatically to be eligible to be citizens (jus soli) even if the parents are not legally present. For example, a child born in the United States to Norwegian parents automatically has dual citizenship with the United States and Norway, even though Norway usually restricts or forbids dual citizenship. There are exceptions, such as the child of a foreign diplomat living in the United States. Such a child would be eligible to become a lawful permanent resident, but not a citizen based on the U.S. birth.^[29]
   This has led to birth tourism, so some countries have abolished jus soli or restricted it (i.e., at least one parent must be a citizen or a legal, permanent resident who has lived in the country for several years). Some countries forbid their citizens to renounce their citizenship or try to discourage them from doing so.^[12]
3. Policy changes may also render people to have multiple citizenship involuntarily, for example, when the sovereignty of a place is changed, the new country may declare the people on it to be citizens of the country.

Complex laws on dual citizenship

Some countries do not simply allow or forbid dual or multiple citizenship in general, but have more complex rules, such as:

• Some countries allow dual citizenship, but restrict the rights of dual citizens:
  • in Egypt dual citizens cannot be elected to Parliament;
  • in Armenia dual citizens cannot vote or be elected to Parliament;
  • in Israel, members of Parliament must renounce any other citizenship before taking their seat in the Knesset;
  • in Australia, dual citizens are ineligible to be elected to the Federal parliament.^[30] In the 2017-18 Australian parliamentary eligibility crisis, fifteen members of Parliament were found to have been ineligible for election due to holding dual citizenship, although most had not been aware of the fact;
  • in New Zealand, dual citizens may be elected to Parliament, but MPs once elected may not voluntarily become a citizen of another country, or take any act to have their foreign nationality recognised such as applying for a foreign passport. However, the only person to recently violate this, Harry Duynhoven, was protected by the passage of retroactive law;
  • In the Philippines, dual citizens may not run for any local elective office.^[31]
  • In the independent states of the Commonwealth Caribbean, nationals of any Commonwealth country who meet local residency requirements are eligible to vote in elections and run for parliament, with one complicated caveat. Each of those countries has a provision barring anyone who "is by virtue of his own act, under any acknowledgment of allegiance, obedience or adherence to a foreign power or state" (to quote a representative provision from the constitution of St Vincent and the Grenadines^[32]) from becoming a member of parliament. The precise meaning of those provisions is disputed, and is the subject of separate ongoing legal disputes in the countries.^[33][34][35]
• Germany and Austria for the most part do not permit dual citizenship except for persons who obtain more than one citizenship at the time of birth.^[36][37] Germans and Austrians can apply for special permission to keep their citizenship (Beibehaltungsgenehmigung) before taking a second one (for example, both Austria and the United States consider Arnold Schwarzenegger a citizen). In general, however, any Austrian who takes up a second citizenship will automatically lose Austrian citizenship. Since August 2007, Germany has recognised dual citizenship if the other citizenship is either one of an EU member country or a Swiss citizenship so that a permission is not required any more in these cases, and in some exceptional cases, non-EU and non-Swiss citizens can keep their old citizenship when they become citizens of Germany. For more details, see German nationality law Dual citizenship. Due to changes of the German law on dual citizenship, children of non-EU legal permanent residents can have dual citizenship if born and grown up in Germany (the foreign-born parents usually cannot have dual citizenship themselves).
• Acquisition of the nationality of Andorra, Portugal, the Philippines, Equatorial Guinea or Iberoamerican countries, is not sufficient to cause the loss of Spanish nationality by birth.^[38] Spain has dual citizenship treaties with Bolivia, Chile, Colombia, Costa Rica, the Dominican Republic, Ecuador, Honduras, Guatemala, Nicaragua, Paraguay, Peru, Puerto Rico and Venezuela; Spaniards residing in these countries or territories do not lose their rights as Spaniards if they adopt that nationality.^[39][40][41] 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).^[42] Upon request Spain has allowed persons from Puerto Rico to acquire Spanish citizenship.^[43][44] On the other hand, foreign nationals who acquire Spanish nationality must relinquish their previous nationality, unless they are natural-born citizens of an Iberoamerican country, Andorra, the Philippines, Equatorial Guinea or Portugal even if these countries do not grant their citizens a similar treatment, or Sephardi Jews. See also the section on "dormant" citizenship.
• Prior to 2011, South Korea did not permit dual citizenship after the age of 21. Now a limited number of persons can have it.^[45] For details, see South Korean nationality law#Dual citizenship.
• Like Germans and Austrians, citizens of South Africa must apply for permission to keep their citizenship when acquiring the citizenship of another country.^[46]
• The Turkish government requires that Turkish citizens who apply for another nationality inform the appropriate Turkish officials (the nearest Turkish embassy or consulate abroad) and provide the original naturalization certificate, Turkish birth certificate, document showing completion of military service (for males), marriage certificate (if applicable) and four photographs. Dual nationals are not compelled to use a Turkish passport to enter and leave Turkey; it is permitted to travel with a valid foreign passport and the Turkish National ID card.
• Pakistan allows dual citizenship with only 19 countries: Australia, Belgium, Bahrain, Canada, Denmark, Egypt, Finland, France, Iceland, Ireland, Italy, Jordan, the Netherlands, New Zealand, Sweden, Switzerland, Syria, the United Kingdom, and the United States.^[47]

Partial citizenship, and residency

Many countries allow foreigners or former citizens to live and work indefinitely there. However, for voting, being voted and working for the public sector or the national security in a country, citizenship of the country concerned is almost always required.

• Since 2008, Poland has granted the "Polish Card" (Karta Polaka) to ethnic Poles who are citizens of the successor states of the former Soviet Union and can prove they have Polish ancestors and knowledge of the Polish language and declare their Polish ethnicity in written form. Holders of the Card are not regarded as citizens, but enjoy some privileges other foreigners do not, e.g. entry visa, right to work, education, or healthcare in Poland. As stated above, Poland currently has no specific laws on dual citizenship; a second citizenship is tolerated, but not recognized.
• Turkey allows its citizens to have dual citizenship if they inform the authorities before acquiring the second citizenship (see above), and former Turkish citizens who have given up their Turkish citizenship (for example, because they have naturalized in a country that usually does not permit dual citizenship, such as Germany, Austria or the Netherlands) can apply for the "Blue Card" (Mavi Kart), which gives them some citizens' rights back, e.g. the right to live and work in Turkey, the right to possess land or the right to inherit, but not, for example, the right to vote.
• 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,^[48] 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 for those born in India with birthrights. Moreover, people who have acquired citizenship in Pakistan or Bangladesh are not eligible for overseas citizenship.

• Many countries (e.g. United States, Canada, all EU countries and Switzerland, South Africa, Australia, New Zealand, and Singapore) issue permanent residency status to foreigners deemed eligible. This status generally authorises a person to live and work in the issuing country indefinitely. There is no right to vote in the host country, and there may be other restrictions (no consular protection) and rights (not subject to military conscription). Permanent residents may usually apply for citizenship after several years of residency. Depending both on the home country and the guest country, dual citizenship may or may not be permitted.

For more details, see Permanent residency.

• Some countries have concluded treaties regulating travel and access to employment: A citizen of an EU country can live and work indefinitely in other EU countries and the four EFTA countries, and citizens of the EFTA countries can live and work in EU countries. Such EU citizens can vote in EU, but not national or local, elections. The Trans-Tasman Travel Arrangement between Australia and New Zealand allows their citizens to live and work in the other country. A citizen of a GCC member state (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates) can live and work in other member states, but dual citizenship (even with another GCC state) is not allowed. Indian citizens do not need a visa to travel to and work in Nepal or Bhutan (and vice versa), but none of the three countries allows dual citizenship.^[49]

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, whereby a country treats a person who is a citizen of both that country and another in the same way as one who is a citizen only of the country. In other words, the country "does not recognize" that the person has any other citizenship for the purposes of the country's laws. In particular, citizens of a country may not be permitted to use another country's passport or travel documents to enter or leave the country.

"Dormant" citizenship and "right of return"

The concept of a "dormant citizenship" means that a person has the citizenships of two countries, but as long as while living permanently in one country, their status and citizen's rights in the other country are "inactive". They will be "reactivated" when they move back to live permanently in the other country. This means, in spite of dual citizenship, only one citizenship can be exercised at a time.

The "dormant citizenship" exists for example in Spain: Spanish citizens who have naturalized in an Iberoamerican country and have kept their Spanish citizenship are dual citizens, but have lost many of the rights of Spanish citizens resident in Spain—and hence the EU—until they move back to Spain. Some countries offer former citizens or citizens of former colonies of the country a simplified (re-)naturalization process. Depending on the laws of the two countries in question, dual citizenship may or may not be allowed. For details, see "right of return".^[50]

Multiple citizenship encouraged

Some countries are more open to multiple citizenship than others, as it may help citizens travel and conduct business overseas. Countries that have taken active steps towards permitting multiple citizenship in recent years include Switzerland (since January 1, 1992) and Australia (since April 4, 2002).^[51][52]

Today, most advanced economies allow dual citizenship;^[53] notable exceptions which restrict or forbid it are Austria, Germany, Japan, the Netherlands, Norway, Singapore, and Spain. Of the newly industrialized countries, Brazil, Mexico, the Philippines, South Africa (with prior permission), Thailand, and Turkey (with prior permission) allow dual citizenship, while China (although Permanent Residents of Hong Kong and Macau may concurrently hold foreign passports), India, and Malaysia forbid it (but all Malaysian and Indian citizens are Commonwealth citizens and are entitled to certain rights in the UK and other Commonwealth countries; Indian citizens may also be regarded as SAARC citizens for some purposes, for example in receiving preferential treatment in obtaining Sri Lankan visas; India allows overseas citizenship – see above). Indonesia allows dual citizenship only until the age of 18 years.^[54]

In former times, some countries (Latin American countries and Canada) advertised their policy of unconditional birthright citizenship to become more attractive for immigrants. Despite wide acceptance of dual citizenship, industrialized countries now try to protect themselves from birth tourism and uncontrollable immigration waves, so only Canada and the United States still grant unconditional birthright citizenship (even for children of illegal immigrants). In both countries, there have been calls to change the laws, but, so far, they have not been successful. Brazil has similar policies; the only people born in Brazil who do not automatically acquire Brazilian citizenship are those whose parents are residing in Brazil while serving their own countries (as diplomats, military attachés, cultural attachés and the like).

In Australia, France, Germany, Ireland, New Zealand, South Africa, and the UK, a child born there is regarded as a citizen only if at least one parent is either a citizen or a legal permanent resident who has lived there for several years. (Germany usually restricts dual citizenship, so non-EU/non-Swiss citizens born and grown up abroad must usually renounce their old citizenship when naturalizing.) Some countries (e.g. Liechtenstein) allow only citizens by descent to have dual citizenship, but require naturalized citizens to renounce their old citizenship.

Former instances

• The use of internal passport to restrict residency and movement in the Soviet Union and in apartheid-era South Africa had the effect of tying local "citizens" to their assigned administrative entity (titular nations and bantustans, respectively).
• 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, Bosnia and Herzegovina, Slovenia, Macedonia, Montenegro) as well as Yugoslav citizenship. In Serbia and Montenegro, this system was in effect until 2006.^[61]
• When Singapore joined Malaysia in 1963, all Singapore citizens were granted Malaysian citizenship. Singapore citizenship continued to exist as a subnational citizenship, and continued to be legislated by the Legislative Assembly of Singapore subject to the approval of the Parliament of Malaysia. Upon Singapore's independence from Malaysia in 1965, Malaysian citizenship was withdrawn from Singapore citizens, and all Singapore citizens became citizens of the new Republic of Singapore.

National cohesiveness

Some have questioned whether allowing dual citizenship impedes cultural assimilation or social integration, increases disconnection from the political process, and degrades national or civic identity/cohesiveness.^[64]

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^[65] and nullifies the consequential, transformational, and psychological change that occurs in an individual when they go through the naturalization process.^[66]

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.^[67] 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.^[68]

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).^[69]

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.^[70]
• The United States is an immigrant nation. As immigration is primarily directed at family reunification and refugee status rather than education and job skills, the pool of candidates tends to be poorer, less educated,^[71] and consistently from less stable countries (either non-democracies or fragile ones) with less familiarity or understanding of American values, making their assimilation both more difficult and more important.^[70]

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. Many countries in Asia such as Japan, China, Taiwan, Singapore 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. Europe is the primary example of this model, where immigrants are usually required to learn the official language, and cultural traditions such as Islamic dress are often barred in public spaces (see Immigration to Europe).^[72][73]
• The multicultural model, which grants immigrants access to citizenship and to equal rights without demanding that they give up cultural, linguistic, or intermarriage restrictions or otherwise pressure them to integrate or inter-mix with the mainstream population. Canada, Australia, New Zealand and the United States have historically taken this approach, as exemplified by the fact that the United States has no official language, allowing official documents such as election ballots to be printed in a variety of languages.^[74] (See Immigration to the United States.)

Appearance of foreign allegiance

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.^[75] However, taking advantage of the entitlements of a non-US citizenship can cause problems. For example, possession 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".^[76]

This guideline has been followed in administrative rulings^[77] by the United States Department of Defense (DoD) Defense Office of Hearings and Appeals^[78] (DOHA) office of Industrial Security Clearance Review^[79] (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 U.S. and Ireland, despite the fact that it has with good relations with the US.^[80]

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.^[81]

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.^[82]

Taxation

In some cases, multiple citizenship can create additional tax liability. Most countries that impose tax normally base tax liability on source or residency. Some countries tax their non-resident citizens on foreign income; examples include the United States and Eritrea.^[99]

• 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 (most common system);
• 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 (as of 2012: only the United States and Eritrea).^[99] A few other countries tax based on citizenship in limited situations: Finland, France, Hungary, Italy, and Spain.

U.S. persons living outside of the United States are still subject to tax on all of their worldwide income, although US law provides measures to reduce or eliminate double taxation issues for some. It has been reported that some US citizens have relinquished US citizenship in order to avoid possible taxes, the expense and complexity of compliance, or because they have been deemed unacceptable to financial institutions in the wake of FATCA.^{[100][101][102]}

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 such citizenship.

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 U.S. 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 U.S. 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 (in 2014, this has now increased to US$97,600).^[103] 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 June 15.^[104]

"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,^[105] Mexico,^[106] 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 US citizens, including dual nationals, must use a US passport to enter and leave the United States.^[107] Under the 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 using 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.

In accordance with the proposed European Travel Information and Authorisation System (ETIAS) that is expected to enter into operation on 1 January 2020, the EU citizens who have multiple nationalities will be obliged to use the passport issued by an EU Member State for entering the Schengen area.^[108]

Military service

Military service for dual nationals can be an issue of concern. Several countries have entered into a Protocol relating to Military Obligations in Certain Cases of Double Nationality established at The Hague, 12 April 1930. The protocol states "A person possessing two or more nationalities who habitually resides in one of the countries whose nationality he possesses, and who is in fact most closely connected with that country, shall be exempt from all military obligations in the other country or countries. This exemption may involve the loss of the nationality of the other country or countries." The protocol has several provisions.^[109]

Healthcare

While the right to healthcare in countries with a public health service is often discussed in relation to immigration, it is a non-issue as far as nationality is concerned; the right to use public health services is determined by legal residency rather than nationality. For example, anyone legally resident and employed in the UK is entitled to use the National Health Service; non-resident British citizens visiting Britain do not have this right.

Africa

Some African countries restrict or forbid dual citizenship.

It is allowed for example in Angola, Burundi, Comoros, Côte d'Ivoire, Djibouti, Gabon, Gambia, Ghana, Kenya, Mali, Morocco, Mozambique, Niger, Nigeria, Rwanda, Senegal, São Tomé and Príncipe, Sierra Leone, Sudan, Tunisia, Uganda and Zambia.

Eritreans, Egyptians, and South Africans^[26] wanting to take another citizenship need a permission to maintain their citizenship. Eritrea taxes its citizens worldwide, even if they have never lived in the country.^[110]

Lesotho restricts dual citizenship, but observes jus soli.

The Americas

Most countries in the Americas allow dual citizenship (some only for citizens by descent or with other countries, usually also in the region, with which they have agreements). Some countries (e.g., Brazil, Bolivia) do not allow their citizens to renounce their citizenship, so they keep it even when naturalizing in a country that forbids dual citizenship. Most countries in the region observe unconditional jus soli, i.e. a child born there is regarded as a citizen even if the parents are not. Some countries (the Dominican Republic, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Uruguay) allow renunciation of citizenship only if it was involuntarily acquired by birth to non-citizen parents.

Canada and the United States allow dual citizenship and are worldwide the only two developed economies to grant unconditional birthright citizenship. The United States taxes its citizens and non-citizen lawful permanent residents worldwide, even if they have never lived in the country. In 2014, the U.S. Department of State increased the fee for processing requests for renunciation of citizenship from $450 to $2,350.^[111][112]

Dual citizenship is restricted or forbidden, for example, in Cuba, Haiti, and Suriname.

Asia-Pacific

Most countries in the Asia-Pacific region restrict or forbid dual citizenship. But in some of these countries (e.g. Iran, North Korea, Thailand), it is very difficult or even impossible for citizens to renounce their citizenship, even when naturalizing in another country.

Dual citizenship is allowed for example in Australia, Fiji, New Zealand, Philippines, Samoa, South Korea, Tonga, and Vanuatu.^[113][114]

Cambodia allows dual citizenship and observes jus soli for children born to legal permanent residents born in Cambodia or to children whose parents are unknown.

Hong Kong allows dual citizenship for citizens by birth but does not permit applicants for naturalization to retain their prior citizenship. However there is not actually a "Hong Kong citizenship". The Nationality law of the People's Republic of China (CNL) has been applied in the Hong Kong Special Administrative Region since 1 July 1997. Hong Kong residents who are Chinese citizens holding foreign passports must make a declaration of change of nationality to the HKSAR Immigration Department in order to be to be regarded as foreign nationals. Foreign nationals or stateless persons can apply for naturalisation as a Chinese national provided that they are Hong Kong residents and meet the requirements under CNL.^[115][116]

South Korea allows any foreign born person meeting income, language, culture, and domicile conditions to become a naturalized citizen. It also allows foreign born nationals who married to a Korean citizen, Korean men holding dual citizenship by birth who served in the Republic of Korea Armed Forces as compulsory military service, Korean women with multiple nationalities by birth who has vowed her intention not to exercise her foreign nationality in the Republic of Korea by the age of 22 and overseas Koreans at least 65 years of age.^[117]

Taiwan^[118] allows dual citizenship for citizens by birth or for its own citizen but do not permit foreign applicants for naturalization to retain their prior citizenship.

Burmese nationality law forbids its citizens to have dual citizenship, and foreigners cannot become naturalized citizens, unless they can prove a close familial connection to the country

Pakistan restricts dual citizenship (see above), but observes jus soli.

In Papua New Guinea there was overwhelming support from parliament to amend their Constitution to allow dual citizenship, however the law had yet to come into force as of February 2014.^[119]

In the Philippines, Republic Act No. 9225, approved 29 August 2003, provided that natural-born citizens of the Philippines who had lost their Philippine citizenship by reason of their naturalization as citizens of a foreign country would be deemed to have re-acquired Philippine citizenship upon taking an oath of allegiance to the Republic, that their children whether legitimate, illegitimate or adopted, below eighteen (18) years of age, shall be deemed citizens of the Philippines, and that natural born citizens of the Philippines who become citizens of a foreign country subsequent to its inactment would retain their Philippine citizenship upon taking the oath.^[120]

Sri Lanka allows dual citizenship.^[121] However, under the 19th amendment of that country's constitution, dual citizens are not allowed to hold public office.

Lebanon allows dual citizenship.

Israel allows dual citizenship.

Iraq allows dual citizenship.

Syria allows dual citizenship.

The Indian constitution does not allow voluntary Dual Citizenship.^[122] However, in response to persistent demands for dual citizenship, particularly from the diaspora in North America and other developed countries, The Overseas Citizenship of India (OCI) scheme was introduced by amending The Citizenship Act, 1955 in August 2005.^[123]

Europe