Being a citizen of the United States and some other country at the same time can be unsettling. If you are, for instance, a national of the US and Great Britain or the US and Mexico, which passport should you use? You need to know the answer especially when traveling abroad between the countries.

The US laws are very clear about which passport you have to use when entering or leaving the United States. Since you are a US citizen, you can’t but use the US passport when you leave and come back to the US. As the US government needs to track down how long you have been out of the United States, the data of your departure will be stored in Advance Passenger Information System (APIS). That is why you should show your US passport when you pass a border control checkpoint or an airport when leaving the US.

Airports in the United States often, if not always, demand that you provide your passport details before you leave, so you will need to fill in a form they provide. Airports simply want your US passport data to know that you are allowed to re-enter the United States, should other country deny you entering it. Therefore, when an airport in the US asks you to provide your passport data, do not use your Canadian, Mexican, or any other passport you might have. Sometimes, you citizenship number, or C-File number, is also required. You can check out this article to know how to find a citizenship number.

But what passport should you use when you are coming from the United States and entering the other country of your nationality? You simply need to show your other than the US passport. For example, if you are entering Great Britain when coming from the United States, hand your British passport to the airport worker.

As you can see, you should follow only two main recommendations: a) always take both passports when you travel from and to the United States; and b) use the US passport for entering and leaving the United States. But when you enter another country of your nationality, always remember to use the corresponding passport.

Now that you know how to handle dual citizenship when traveling to and from the United States, check out our service and apply for US citizenship.