Holding two passports sounds simple enough these days, especially with so many countries loosening their nationality rules in recent years. Germany’s 2024 reform made headlines precisely because it flipped a long-standing European holdout into a dual-citizenship-friendly nation almost overnight. Yet a meaningful slice of the world still treats a second passport as something closer to a legal problem than a lifestyle choice, and the reasons behind that stance are more varied than most people assume.
1. China
China’s position on dual nationality is about as unambiguous as national law gets. The Chinese Nationality Law clearly affirms in Article 3 that the People’s Republic of China does not recognize dual nationality for any Chinese national. The moment a Chinese citizen naturalizes elsewhere, the switch flips automatically, no paperwork required on Beijing’s end to make it official.
That automatic loss creates a quiet trap for people who keep using their old Chinese passport out of habit. Continuing to use a Chinese passport after acquiring foreign citizenship is risky, because that Chinese nationality was automatically lost at the moment of naturalization, meaning the passport is no longer valid even if it hasn’t expired on its face. Getting caught with an invalid document at the border isn’t just embarrassing, it can trigger real fines and in serious cases short-term detention.
2. Japan
Japan’s approach is less about an outright ban and more about a deadline. Japan’s nationality law generally prohibits dual citizenship, and Japanese nationals must choose one nationality by age 22 if they hold multiple citizenships. For people born to one Japanese and one foreign parent, this isn’t a hypothetical, it’s a real administrative clock ticking in the background of their early adult life.
What makes Japan an interesting case is the gap between the letter of the law and how it actually plays out. Despite the strict legal framework, enforcement of the dual nationality prohibition is famously inconsistent, and the Justice Ministry has confirmed that approximately 890,000 people were or are in a position to hold dual nationality in Japan. So the rule exists, and it’s real, but a lot of people quietly live in the space between compliance and enforcement.
3. India
India draws its line directly from the constitution rather than leaving it to administrative discretion. If you hold Indian citizenship and voluntarily acquire a foreign passport, your Indian citizenship ends automatically under Article 9 of the Indian Constitution, with no application, grace period, or exception. It’s a clean, immediate cutoff the moment someone naturalizes abroad.
India has softened the blow somewhat through a workaround rather than a rule change. India offers Overseas Citizenship of India, a permanent-residency-like status that gives people of Indian origin most practical benefits of living and working in India without actual citizenship. It’s not dual citizenship in any legal sense, but it’s the closest thing New Delhi has been willing to offer the diaspora so far.
4. Singapore
Singapore treats dual nationality as something children can hold temporarily, but adults cannot keep indefinitely. Children may have dual citizenship in Singapore, but by the age of 21, a Singapore citizen must choose which nationality to renounce. It’s a built-in coming-of-age decision that most other countries simply don’t require of their young people.
This isn’t a loophole citizens can quietly ignore the way some do in Japan. Legal advisors who work with Singaporean families routinely stress that Singapore is one of the countries where dual citizenship planning should begin early, not at the deadline. Given the country’s mandatory national service obligations for young men, the stakes around that choice tend to be taken seriously well before the deadline arrives.
5. Saudi Arabia
Saudi Arabia’s restriction is framed around loyalty and national security rather than administrative tidiness. Saudi Arabia upholds a stringent policy against dual citizenship, reflecting broader concerns about national security and social stability, and views dual nationality as a potential source of divided loyalties. Anyone seeking Saudi nationality is generally expected to commit to it fully, which in practice means giving up whatever citizenship they held before.
The enforcement side can be surprisingly direct. According to reporting drawing on US State Department guidance, Saudi Arabia has a habit of banning dual nationality for its citizens, and Saudi authorities have confiscated American citizens’ passports when they apply for Saudi citizenship. There are narrow exceptions, mostly involving children born in the kingdom to foreign parents, but for most adults the choice is binary.
6. Austria
Austria stands out because it’s one of the few Western European countries that hasn’t followed the continent’s broader drift toward accepting dual nationality. Austria prohibits dual citizenship except by special government permission. That permission tends to be granted sparingly and usually only in cases involving exceptional merit or specific personal circumstances.
The contrast with Germany next door is notable, since Berlin reformed its own rules in 2024 while Vienna held firm. People pursuing Austrian citizenship through investment or residency routes are generally told upfront that renunciation of their existing nationality is part of the deal, with exceptions reserved for unusual cases rather than treated as a routine option.
7. Indonesia
Indonesia draws a fairly clean age-based line similar in spirit to Japan and Singapore, though the country frames it purely as a rule for adults. Indonesia does not permit dual citizenship for adults, though children of mixed-nationality parents can hold dual citizenship until age 18. Once that threshold passes, the choice has to be made, and there’s no ambiguous middle ground the way there sometimes is elsewhere.
For Indonesian nationals who move abroad and naturalize as citizens of another country, the practical result tends to mirror what happens in China and India: the original citizenship is treated as forfeited rather than simply set aside. It’s a policy rooted less in security anxiety and more in a straightforward preference for singular national identity, particularly among a population with such a large overseas diaspora.
These seven countries approach the same underlying question, whether a person can belong fully to two nations at once, from noticeably different angles. Some frame it as a security matter, others as a question of loyalty or national identity, and a few simply build a deadline into the law and let individuals sort it out for themselves. What ties them together is that in each case, the paperwork is only part of the story. Real consequences, from invalid passports to automatic loss of status, tend to follow anyone who assumes a second citizenship is just an extra document in a drawer.
