Crossing international borders usually involves some kind of checkpoint—and since international airports are the first point of entry to a new country, they have checkpoints in them through which travelers must pass before they leave the airport. Collectively, these are typically referred to as customs and immigration.
Officials at customs and immigration are checking travelers for things like whether they have the right documents to be in the country, whether they’re legally allowed to be there, and whether they’re bringing anything illegal with them.
You’ll go through customs and immigration both ways on an international trip—when you arrive in the foreign country you’re visiting, and again when you return to your home country from abroad.
“Immigration” is about the people traveling from one country to another. It’s sometimes called “passport control” or “border control” depending on the airport. “Customs” is about the stuff those people are carrying with them.
In many airports, immigration is a mandatory process that involves speaking with an immigration officer who stamps your passport, while customs is an optional process; if you have nothing to declare, you don’t need to speak with an officer. You can go through immigration without your luggage, but customs will be located after baggage claim.
In most cases, you’ll go through customs and immigration after your flight first arrives in a new country, but there are exceptions.
For example, some countries have mutual agreements intended to help speed travelers through the process, so you may go through customs and immigration before you board. When flying from Ireland to the United States, for instance, you’ll go through US customs in Ireland. But when arriving to the US from most other countries, you’ll go through customs upon your first arrival in the US (even if you have a connecting flight onward).
And sometimes you don’t go through customs until you reach your final destination. For example, if you’re flying from the US to Europe and have a layover in one Schengen Area country before you arrive in a second Schengen Area country, you’ll typically go through immigration when you first land, but you won’t go through customs until you reach your final destination.
Upon arriving at the desk of an immigration agent in your destination airport, you’ll likely be asked a variety of questions (in some cases you may not be asked anything at all, but that’s increasingly rare). You may be asked whether your trip is for business or pleasure, how long you’ll be in the country, what you do for a living, and what cities you’ll be visiting during your stay.
When you go through the same process on your way home, you’ll be asked a similar set of questions—such as where you were on your trip, how long you spent there, and what you’re bringing back with you. This last question is often phrased as, “Do you have anything to declare?”
Customs fees, or customs duty, are essentially taxes on goods you bring with you across international borders. In most cases, goods that travelers bring back from vacation are meant for personal use and are in small enough quantities that they won’t incur any fees. In other cases, there’s a threshold above which travelers must pay a fee. Alcohol and tobacco, for instance, have a customs duty depending on how much you bring with you.
It’s a little easier to talk about the things you can’t bring through US customs.
The United States limits the amount of alcohol travelers can bring with them into the country. You can bring one liter duty-free, and after which a customs duty of 3% per liter is imposed. Tobacco products also have individual limits, typically 200 cigarettes and 100 cigars per person. Anything above that, rather than being taxed, may be confiscated.
Meat and produce are generally prohibited, though there are some exceptions for cured or processed products depending on how they’re packaged. Cheese can be problematic, too.
Plants are a no-no (they might be ferrying unwanted pests), which means some crafts made from plant materials (like woven baskets or hats) aren’t going to make it through customs, either.
Depending on where you’re coming from, some pieces of art may get you into trouble at customs—because the country you’re departing has expressly forbidden items it deems “cultural treasures” to leave its borders.
Check the US Customs and Border Protection list of “Prohibited and Restricted Items” to find out what should (and shouldn’t) be on your shopping lists when you travel.
When you’re asked if you have anything to declare, these are some of the things that will require a “yes.”
You can read a more detailed list here.
If you have a prohibited item in your bag and you declare it, the only penalty is that you’ll need to give up that item.
If you’ve got something in your bags that you didn’t declare and you should have, the penalties can vary.
Without any prior record of trying to skirt customs rules, you may get a simple warning if all you did was forget to eat that French apple before you got on the plane. If it’s not your first time getting caught, however, you may well get hit with a fine of a few hundred dollars or more. Meat, cheese, and produce sometimes come with fines of as much as $10,000.
Because these infractions get recorded, you may get more intense scrutiny during customs or security checks on future flights for some time, and in some rare cases, travelers who have Global Entry or TSA PreCheck run the risk of having that “trusted traveler” status removed, losing their membership in the program, and being unable to get that status again for a set period of time.