Quick answer
Reviewed · 4 min read
US law requires US citizens, including dual nationals, to use a US passport to leave and enter the United States. Your other country may likewise require you to use its passport there. Carry both, keep them valid and, ideally, in the same name. Abroad, show the passport that best supports entry to that country, and know that consular help can be limited in your other country.
Researched and maintained by Empyrean Travel · How we research
- Leaving and entering the US
- US passport required
- Your other country
- May require its own passport
- Best practice
- Carry both, both valid
- Consular help
- Can be limited in your other country
Which passport do you use to leave and enter the US?
Your US passport, every time. The State Department is clear that US nationals, including dual nationals, must use a US passport to enter and leave the United States. Don’t try to enter on your other passport; as a US citizen you aren’t eligible for an ESTA or a visitor visa.
Trusted traveler programs follow the same rule. Global Entry and Mobile Passport Control are linked to your US passport, so keep that passport’s details current in your profiles.
Which passport do you show when you travel abroad?
When you visit your other country of citizenship, it may require you to enter and leave on its passport, and some countries don’t recognize dual nationality at all. Check that country’s embassy rules before you go.
For third countries, you can usually choose whichever passport gives easier entry. An EU passport, for example, lets you use EU lanes and means you won’t need ETIAS, the EU’s planned travel authorization, which isn’t operating as of October 2026; see EES and ETIAS explained. Whatever you choose, leave a country on the same passport you used to enter it, so the exit matches the entry record.
How should dual citizens book international flights?
Book in a name that matches both passports if possible. If they differ, use the name on the passport you’ll show at check-in for that flight. Airlines must confirm you can enter your destination, so at check-in, show the passport that proves your right to enter there, and keep the other one handy.
Leaving the US, you may be asked for both: the US passport for US departure records and the other for your destination. Being upfront at the counter avoids confusion. Our guide to name mismatches on tickets covers what to do if your passports show different names.
What obligations and risks come with a second citizenship?
While you’re in your other country, its laws apply to you as a citizen. Depending on the country, that can include military service obligations, tax rules or exit requirements. US law doesn’t require you to choose one nationality, and the State Department says using a foreign passport doesn’t by itself endanger US citizenship.
Consular help can be limited. Your other country may treat you solely as its own citizen and restrict US embassy access to you. Read the State Department travel advisory for that country, which sometimes addresses dual nationals directly, and enroll in STEP.
What should dual citizens check before every trip?
A short checklist prevents most problems.
- Both passports are valid for at least six months beyond your trip
- The names on both passports match, or you know which name each booking uses
- Renewal timelines for your other passport, which can take far longer than US renewals
- Your children’s status and passports in both countries, if they’re dual nationals too
- Entry rules in your other country for citizens who live abroad
Frequently asked questions
Can I enter the US on my foreign passport if I’m a dual citizen?
Do I need a visa if I travel on my other passport?
Will having two passports cause problems at the airport?
Does using a foreign passport affect my US citizenship?
Can the US embassy help me in my other country of citizenship?
Official sources
Rules, fees and schedules change — confirm the latest details at the source before you travel.