Dual citizenship in Singapore is not allowed for adults. A child can hold Singapore citizenship alongside another nationality for a while, but by the 22nd birthday a citizen by descent or registration has to give up the foreign one and take an oath before ICA, or the Singapore citizenship lapses. Adults who take up another nationality by choice can be stripped of Singapore citizenship under the Constitution.
That short answer covers most cases. The rest of this guide goes through who the rules touch, the age deadline, what counts as using a foreign citizenship, how new citizens and permanent residents fit in, and the documents ICA asks for. Every rule here comes from ICA or the Constitution of the Republic of Singapore, checked as of October 2026.
Key Takeaways
- Singapore does not allow an adult to hold Singapore citizenship and another citizenship at the same time.
- Citizens by descent or registration who also hold a foreign nationality must take the Oath of Renunciation, Allegiance and Loyalty after turning 21 and before turning 22.
- Miss that window and Singapore citizenship is lost automatically on the 22nd birthday, per ICA.
- Using a foreign passport or claiming rights reserved for foreign citizens as an adult are grounds on which the Government may remove citizenship.
- Permanent residents are not dual citizens. PR is a residence status held alongside your own nationality.
- Male citizens with unfinished National Service may have a renunciation application withheld.
What the Constitution says about two citizenships
There is no single line in Singapore law that reads "dual citizenship is banned". The effect comes from Part 10 of the Constitution, which sets out how citizenship is gained and lost. Two articles do most of the work.
Article 134: taking up another citizenship
Article 134 lets the Government, by order, deprive a citizen of Singapore citizenship if it is satisfied the person, at 18 or older, gained another country's citizenship by registration, naturalisation or another voluntary and formal act other than marriage. It also covers a person who acquired a foreign citizenship before 18 and keeps it after that age.
Article 135: acting as a foreign citizen
Article 135 covers conduct rather than paperwork. After 18, voluntarily claiming and using rights that another country gives only to its own citizens can be grounds for deprivation. So can getting or renewing a foreign passport, or travelling on one. Both articles say the Government may act. They describe a power, so the outcome turns on the facts ICA has in front of it.
In practice this means a Singaporean adult who quietly renews a second passport is taking a real risk, even if nobody has asked about it yet.
Children with two nationalities and the age 22 deadline
Many families first meet these rules when a child is born overseas, or born to one Singaporean parent and one foreign parent. The child may pick up a second nationality automatically from the other parent or from the place of birth, and Singapore tolerates this while the child is young.
ICA's guidance on oath-taking for minors says that people who obtained Singapore citizenship by descent or registration must take the Oath of Renunciation, Allegiance and Loyalty (ORAL) after turning 21 and before their 22nd birthday to keep it. If the oath is not taken within those 12 months, Singapore citizenship is lost automatically on the 22nd birthday.
| Age | What happens | Source |
|---|---|---|
| Birth to 18 | Holding two nationalities is tolerated for a child | Constitution, Articles 134 and 135 apply from 18 |
| 18 to 21 | Using a foreign passport or claiming foreign citizens' rights can count against Singapore citizenship | Constitution, Article 135 |
| 21 to before 22nd birthday | Window to renounce the foreign nationality and take the ORAL | ICA, oath-taking for minors |
| 22nd birthday | Singapore citizenship lapses if the oath was not taken | ICA, oath-taking for minors |
What to bring to the oath
ICA lists two documents for the ORAL: the Singapore Identity Card and a Foreign Citizenship Renunciation Certificate. That second document comes from the other country, so the foreign renunciation has to be done first, and some countries take months to issue it. Start that process well before the 21st birthday.
In Singapore the oath is taken in person at the ICA Services Centre, 2 Crawford Street. Overseas, it can be taken at the nearest Singapore Overseas Mission. ICA charges no fee and completes it the same day.
Citizens by birth
ICA's oath page names citizens by descent and by registration. If your child is a citizen by birth and also holds another nationality through a parent, write to ICA and get its answer for your child's case in writing. Article 135 still applies to everyone once they turn 18.
New citizens and permanent residents
Becoming a citizen means giving up the old passport
A permanent resident who applies for Singapore citizenship and is approved receives an In-Principle Approval first. ICA says applicants are granted citizenship once they have fulfilled the conditions, and that applicants aged 16 to 60 must complete the Singapore Citizenship Journey. The oath a new citizen takes is the same Oath of Renunciation, Allegiance and Loyalty set out in the Second Schedule of the Constitution, so plan on giving up your current nationality. Follow the steps in your own approval letter, since it is the document ICA will hold you to.
Before applying, check what your current country does when you leave. Some countries restrict property ownership or inheritance for former nationals. That is a question for your current government, and it should be answered before you submit.
| Citizenship application item | Amount or time (ICA, as of 2026) |
|---|---|
| Application fee, adult PRs and children of PRs | S$100 per application |
| Singapore Citizenship Certificate | S$70 |
| Singapore Identity Card, new citizens aged 15 and above | S$10 |
| Overseas-born child of a Singapore citizen | S$18 per application, certificate included |
| Processing time, most applications | Within 12 months |
| Decision time, overseas-born child of a citizen | Within 1 month if documents are in order |
PR is not a second citizenship
Permanent residence is a residence status. A PR keeps their own nationality and passport, and needs a valid Re-Entry Permit to keep the status while travelling. So a PR is not a dual citizen, and nothing in the PR rules asks you to give up your nationality. The trade-off is that PR does not carry a Singapore passport or the right to vote.
Renouncing Singapore citizenship instead
Some people choose the other passport. ICA allows a citizen to renounce only if the person is 21 or older, of sound mind, and has already acquired another country's citizenship. You cannot renounce first and look for a new nationality later.
Renunciation is done through ICA's online portal and takes about 30 minutes to fill in, with no save function. ICA asks for certified true copies of the foreign citizenship certificate and foreign passport, and the originals of the Singapore Identity Card, passport and any citizenship certificate must reach ICA before the case is processed.
National Service and renunciation
ICA states that the Government may reject the renunciation of a male citizen who has enjoyed the privileges of citizenship, such as holding or using a Singapore passport, and still has National Service obligations outstanding. Leaving without serving also has long-term effects. ICA says renouncing or losing citizenship or PR without completing full-time NS will hurt later applications to work, study or live in Singapore, and can affect family members' applications too.
How to check your own position
Most problems start with an assumption, such as a parent thinking a child born abroad is "just Singaporean", or an adult thinking a second passport is fine as long as it stays in a drawer. The list below is the check we run with families before any application goes in.
- For each family member, write down every nationality they hold or could claim through a parent or their place of birth.
- Note how each person became Singaporean: by birth, descent or registration. The oath rules ICA publishes name descent and registration.
- Mark the 21st birthday of every child with a second nationality, and find out how long the other country takes to issue a renunciation certificate.
- Stop using any foreign passport once you turn 18 unless ICA has told you in writing that your case allows it.
- If you are unsure of your status, ICA issues a digital letter confirming Singapore citizenship status for S$20, usually in three working days.
What is changing
There has been no change to the no-dual-citizenship position, and nothing on ICA's pages as of October 2026 suggests one. The working details, such as fees and forms, do change from time to time, so check ICA's current page before you act.
Frequently Asked Questions About dual citizenship in Singapore
Does Singapore allow dual citizenship?
Not for adults. Children can hold two nationalities for a time, but citizens by descent or registration must renounce the foreign one and take the Oath of Renunciation, Allegiance and Loyalty before turning 22, per ICA.
What happens if my child misses the oath before 22?
ICA says that if the oath is not taken within 12 months of turning 21, Singapore citizenship is lost automatically on the 22nd birthday, and there is no guarantee of being able to study, work or live in Singapore afterwards.
Can I keep my foreign passport after becoming a Singapore citizen?
No. New citizens take the Oath of Renunciation, Allegiance and Loyalty, and using a foreign passport as an adult is a ground on which the Government may remove citizenship under Article 135 of the Constitution.
Is a Singapore PR a dual citizen?
No. Permanent residence is a residence status held alongside your own nationality. You keep your passport and need a valid Re-Entry Permit to keep PR while travelling.
Can I renounce Singapore citizenship before getting another one?
No. ICA only accepts renunciation from a citizen who is 21 or older, of sound mind, and has already acquired another country's citizenship.
Does National Service affect renouncing Singapore citizenship?
Yes. ICA says the Government may reject a male citizen's renunciation if he has enjoyed citizenship privileges, such as a Singapore passport, and still has NS obligations outstanding.
Official Sources and References
- Oath-taking for minors (ICA)
- Renunciation of Singapore citizenship (ICA)
- Becoming a Singapore citizen (ICA)
- Letter confirming citizenship status (ICA)
- Constitution of Singapore, Articles 134 and 135 (Singapore Statutes Online)
Explore Catalyst Immigration’s other services:
- Renouncing Singapore citizenship
- Singapore citizenship for a newborn
- Singapore PR vs citizenship
- National Service for PRs in Singapore
- Citizenship application service
Talk to Catalyst Immigration
If your family has a child with two nationalities, or you are weighing Singapore citizenship against the passport you hold now, Catalyst Immigration can walk through the dates and documents with you. ICA makes every decision, and we help you reach it with the right paperwork in hand.