How the U.S. Customs Service Works

Cars line up at the CBP inspection station at San Ysidro, Calif., thought to be the busiest landport in the world.
Cars line up at the CBP inspection station at San Ysidro, Calif., thought to be the busiest landport in the world.
John Denmark/U.S. Customs and Border Protection

You're still wearing a sombrero as you queue in a U.S. airport customs line, clinging to the last vestiges of the week you spent in paradise. But as you near the U.S. Customs and Border Protection agent, you wonder if admitting your vacation is over is the only thing you'll need to declare. What about that bottle of rum in your suitcase? The sand you swiped from the beach and put in a plastic baggie as a souvenir? And there's the starfish you bought in the hotel gift shop. Maybe it isn't just the heat that's making you sweat.

If you've ever entered the United States (as a visitor or citizen returning home), you encountered the U.S. Customs and Border Protection (CBP) on your way back home. You probably are most familiar with the role of these uniformed men and women as they check the declaration form you filled out on the airplane, and perhaps examine your luggage to be sure nothing illegal is tucked inside. Remember that starfish? It may be contraband. And the medication your traveling companion bought at a Mexican pharmacy because it was cheaper than buying it in the U.S.? He may have some trouble getting it across the border without a prescription.


U.S. customs officers do far more than simply stand around at airports or border stations and look through people's bags. They enforce hundreds of laws for 40 different government agencies and prevent thousands of cases of illegal smuggling each year. In fact, the CBP assesses all people who arrive by airplane, overland vehicle, ship or on foot and want to enter the U.S. The job of U.S. customs agents is to search for banned agricultural products and counterfeit goods, but they also are trained to seize street and pharmaceutical drugs, illegal immigrants and traffickers and to spot terrorist risks [sources: U.S. Customs and Border Protection, Wallechinsky].

What Is the U.S. Customs Service, and How Long Has It Been Around?

A Border Patrol agent inspects a man-made tunnel near Nogales, Ariz. Such tunnels are used to transport drugs under the U.S. border.
A Border Patrol agent inspects a man-made tunnel near Nogales, Ariz. Such tunnels are used to transport drugs under the U.S. border.
John Denmark/U.S. Customs and Border Protection

On July 4, 1789, the First Congress passed, and President George Washington signed into law, the Tariff Act of 1789. This act authorized the collection of duties, or fees, on imported goods. (The act was proposed as a measure to raise money for the financially desperate young nation.) Points of entry were determined shortly after, and people -- citizens and visitors -- entering the U.S. began to be accountable for what they brought with them [source: Malloy].

For more than a century, U.S. Customs supported virtually the entire government and its infrastructure, according to Customs Service historians. Customs revenues were used to build Washington, D.C., many of the nation's lighthouses, and the U.S. military and naval academies.


The U.S. Customs Service, whose early activities were far-reaching and diverse, spawned other government agencies, including the Bureau of Census, the Department of Veterans Affairs, the U.S. Coast Guard and the National Institute of Standards and Technology.

In March of 2003, the U.S. Customs Service (along with employees from other organizations like the U.S. Border Patrol) became U.S. Customs and Border Protection, an agency of the Department of Homeland Security. With that update, the CPB became responsible for ensuring that all imports and exports are legal and comply with U.S. laws and regulations, and for collecting revenues associated with the enforcement of those laws. (Zachary Mann, a 13-year special agent and spokesman for the U.S. Customs Service, likes to describe the agency as the "oldest law enforcement agency" in the U.S.)

The agency also takes charge of the following activities [source: Wallechinsky]:

  • Seizing contraband, including illegal drugs and narcotics, and arresting people engaged in smuggling or other fraudulent behavior with the intent to get around customs laws
  • Processing people, luggage, cargo and mail
  • Protecting U.S. business and intellectual property rights by enforcing laws aimed at preventing illegal trade practices
  • Protecting the "general welfare and security" of the U.S. by enforcing import and export prohibitions and restrictions, including money laundering and the export of data essential to the production of mass weapons of warfare
  • Gathering import and export data for the purpose of compiling international trade statistics
  • Enforcing hundreds of laws -- many related to quality of life issues, such as pollution and health -- for approximately 40 other agencies

What Does U.S. Customs Investigate?

U.S. Customs and Border Protection, which describes itself as "the primary enforcement agency protecting the nation's borders," has extensive air, land and marine resources -- including such state-of-the-art equipment as unmanned aerial vehicles -- for enforcing laws, as well as its own intelligence branch. Plus, it has an extensive canine corps for sniffing out drugs and other illegal substances [source: U.S. Customs and Border Protection].

Special agents deal with major criminal activities, including money laundering, drug smuggling, child pornography and what are known as exodus cases. Exodus cases involve the export of arms, weapons systems and other technology that can be used militarily against the U.S., according to customs agent Mann.


Another major area of investigation is commercial fraud. For example, in the Carolinas, special agents investigated people who brought in textiles illegally from other parts of world in attempts to beat the U.S. visa quota system, Mann says. As an illustration, let's say that a foreign manufacturer of textiles in Asia has a bilateral textile agreement with China and the United States. This bilateral agreement is part of a quota visa program, which says textiles imported into the United States must have a visa against that quota.

"Unfortunately, there are unscrupulous importers who purchase textiles from China, ship them to a third country and try to import them into the United States as products of that third country," Mann says. "This undermines the visa quota program and brings goods in that compete directly with our own textile capabilities. Millions and millions of dollars can be at stake here."

Similarly, commercial fraud is being conducted around the import of plain white T-shirts. (These are a hot commodity -- statistics say that the average American consumes 15 T-shirts a year from sporting events, concerts and work.) If T-shirt printers can get cheaper shirts brought in and evade duty rates, they can be more competitive.

What Do I Need to Know Before I Travel Abroad?

A CBP office checks a passenger's luggage and documents.
A CBP office checks a passenger's luggage and documents.
U.S. Customs and Border Protection

Before you leave for vacation -- or even before you pack your bags -- you should know some of the laws that will affect you when you return to the U.S. from a foreign country. First of all, it's a good idea to take only the amount of personal medications that you'll need during your trip. In order to avoid customs problems, experts say you should leave each medication in its original container so that the drug name, dosage and physician's name are available for checking. Very large amounts of medications may raise "red flags" with customs officers. If you must carry these, take along a letter from your doctor and copies of your prescriptions.

Also, when you're packing, examine any electronics or expensive camera equipment you might be taking along. If that laptop was made in another country, you should register your ownership of it (complete with serial number or some other distinguishing mark) before you leave the U.S. (Customs provides special forms, Form 4457, for this purpose and you must show the item you're registering to an official). This certificate can be used on future trips. Without proof of ownership, you could be asked to pay duty on it again when you return home [source: U.S. Customs and Border Protection]. Other acceptable proofs of ownership include insurance documents, sales receipts and jewelry appraisals.


Mann, who is based in the Miami Customs office, emphasizes the importance of keeping your bags with you at all times when traveling and of refusing to accept bags or packages from strangers. There are reasons why airline agents ask if you've packed your own bags and kept them with you, and why airport announcements continually remind you that bags left unattended will be confiscated by airport security, he says. "Whether you're traveling outside the United States or inside, you don't want to carry or take someone else's bags or luggage or leave your own bags unattended. When you leave your bag unattended, this allows the opportunity for someone to put drugs inside it."

For a complete list of what you should know before you travel, check out the U.S. Customs and Border Protection Know Before You Go information. Another important bit of advice: If you observe suspicious activity or have information about smuggling or other fraudulent activities, call the Customs Service to report it at 1-800-Be-Alert. Information on reporting specific types of activity, including child kidnapping or exploitation, or illegal aliens, can by found on the U.S. Customs and Border Protection Web site.

What Must I Declare?

It's very important to know what you must declare or reveal on an official CBP declaration form (informally called the "customs form") before re-entering the country by plane or ship. You may bring foreign currency back into the United States, but you must declare all monetary instruments including traveler's checks, money orders, gold coins, cash, checks, promissory notes, securities or stocks. There is no limit to the amount of money that can be brought across the U.S. border, but if you have more than $10,000 you must report it to the CBP on your declaration form [source: U.S. Customs and Border Protection].

Otherwise, anything that you did not have when you left the country must be declared, including:


  • Anything you bought (including from duty-free shops or on a ship or airplane)
  • Anything you inherited or received as a gift (you'll have to estimate the fair market price of the gift)
  • Anything you brought home for a friend
  • Anything you plan to use or sell in your business
  • Alterations or repairs to anything you took abroad and brought back (for example, tailoring of a suit in Hong Kong)
  • Anything you bought (or received as a gift) in an insular possession country (America Samoa, Guam, the U.S. Virgin Islands) or any Caribbean Basin Initiative country (see the sidebar) and that is being shipped directly to your home (this is different from the usual procedure for mailed items)

All this means that you should save your sales receipts (no matter what language or currency) in case you're asked to produce them and that you should pack the items you're declaring separately (perhaps in a carry-on bag) in case officials want to see them.

You declare these items by filling out the U.S. customs form you will receive on the airplane or in the airport before you arrive at the customs area. The form, which also asks for basic information related to your trip, requires that you list each item in the above list and how much it cost. If you're traveling with your immediate family, personal exemptions may be combined on one form [source: U.S. Customs and Border Protection].

What Does Duty-free Mean?

Depending on the country you are returning from when you enter the U.S., your personal duty-free exemption will be $200, $800 or $1,600. This personal duty-free exemption is the total value of the merchandise you're allowed to bring back into the country without paying additional duty. There are limitations on how much alcohol and tobacco products can be included in this total, which we will explain later.

You are eligible for your personal exemption if you meet the following criteria:


  • Items are for your personal use or use in your home.
  • You have been out of the country for longer than 48 hours. (The 48-hour rule is waived for visits to Mexico.) If you've been away for less than 48 hours, you may be eligible for a $200 exemption, but you are not allowed to group your family's exemptions together.
  • Items are physically with you. Purchases that are being shipped to your home may not be included in your personal exemption, with the exception of those shipped from a Caribbean Basin Initiative country or insular possession. You can, however, lighten your load by mailing home your dirty clothes, as long as they were made in the United States and haven't been altered. You can claim duty-free status by labeling your package "American Goods Returned."
  • You haven't used your exemption, or any part of it, in the past 30 days. If you have, you must wait another 30 days before you are eligible for another $800 exemption. However, you may qualify for a $200 exemption, with all the same limits on amounts of alcohol and tobacco products applying.
  • You have declared all items that you did not have when you left the United States, even if you're wearing them.

Overall, if you're not sure whether something should be declared, customs officials say that it's better to err on the side of making that declaration. Otherwise, you risk being perceived as trying to pull a fast one on the officials and having the item in question taken away [source: U.S. Customs and Border Patrol].

Don't be confused by the term "duty-free shops." It doesn't mean that what you buy in duty-free shops won't be subject to duty when you return to the United States -- it will. Merchandise sold in duty-free shops are free of duty and taxes only for the country in which that shop is located. So if your purchases exceed your personal exemption, items you bought in a duty-free shop, whether in the United States or abroad, will be subject to duty.

Sometimes a duty-free purchase is a good deal; sometimes it's not. Many veteran travelers find perfume, cosmetics and premium liquors -- all of which are subject to duty -- to be good buys in duty-free shops. You might also find items you've never seen, since sometimes products are test-marketed at duty-free shops before they are sent to local stores. Generally, it's a good idea to check out other stores before you make a large purchase in a duty-free shop -- you may find better deals elsewhere [source: Cheng].

The $800 Personal Exemption, Tobacco and Alcohol

In most cases, travelers entering the U.S. are eligible for an $800 exemption if returning from any country other than a U.S. insular possession. This eligibility applies only to items that you actually have in your possession. Items that you mail home to yourself follow these duty-free guidelines [source: U.S. Customs and Border Protection]:

• If purchased from an insular possession, up to $1,600 in goods may be mailed duty-free. The amount you mail counts as part of your $1,600 duty-free total.


• If purchased from a Caribbean Basin Initiative country, up to $800 in goods may be mailed duty-free. The amount you mail counts as part of your $800 duty-free total.

• To get this benefit, you'll need to ask the merchant to hold the item. Next, fill out Form 255 when you clear customs, listing the value of the item. Then, send a copy of the form to the overseas merchant so he can mail you the item, with the form attached in an envelope to the outside of the package.

• For other countries (or if the package has already been mailed), you'll pay duty to the U.S. post office or freight service, as needed, when the item is shipped to you.

Tobacco -- Your $800 duty-free exemption may include up to 200 cigarettes and up to 100 cigars. If you bring more than that, you'll have to pay duty on them, even if you haven't gone over your total exemption. (You may also have to pay state or local taxes on tobacco products) [source: U.S. Customs and Border Protection].

Federal laws states that you may not bring back cigarettes that you purchased in another country if they were manufactured in the United States for export purposes. That definition includes most cigarettes you would find sold in stores; an exception (a rare one) might be cigarettes someone purchased in the United States, took to another country and tried to sell, Mann says. You'll know the difference because cigarettes made for export purposes don't generally bear the Surgeon General's Warning label or tobacco seal; cigarettes purchased in the U.S. must have these stamps. All tobacco products made in Cuba are prohibited [sources: U.S. Customs and Border Protection, U.S. Customs and Border Protection].

Alcohol -- You are allowed to bring in 1 liter (33.8 fluid ounces) of an alcoholic beverage (liquor, beer, wine) as part of your duty-free exemption if you are 21 or older and the beverage is a gift or for your own use. (This allowance is subject to state laws -- check yours before you leave on your trip. If returning from an eligible Caribbean Basin country, you are allowed 2 liters (68 fluid ounces) duty-free, as long as one of the bottles was produced in the country. If returning from a U.S. insular possession, such as the U.S. Virgin Islands, American Samoa or Guam, you can carry up to 5 liters (169 fluid ounces) of alcohol across the border as part of your $1,600 duty-free exemption, as long as 1 liter was produced in a possession [source: U.S. Customs and Border Protection].

If you want to bring back more for your personal use -- unusually large amounts raise red flags about your intentions for the product -- you can. But you will be charged duty and Internal Revenue Service tax. (The U.S. Customs and Border Protection enforces these laws on behalf of the Bureau of Alcohol, Tobacco, Firearms and Explosives. This means they are within their rights to decide that these products are being brought in for commercial purposes and to hold the alcohol until you obtain a permit to import it.) Finally, importation of absinthe, a potent green liqueur flavored with European wormwood, or any other liquor or liqueur containing an excess of Artemisia absinthium (wormwood) is prohibited [source: U.S. Customs and Border Protection].

Firearms -- Under Federal Aviation Agency (FAA) regulations, no U.S. commercial airline allows firearms in its airplane cabins except in the possession of law enforcement officers. ATF also regulates and restricts firearms and ammunition and approves all import deals involving weapons and ammunition, which must be arranged by a certified arms dealer. There are some exceptions for antique firearms, which are outlined in Chapter 93 of the Harmonized Tariff Schedule [source: U.S. Customs and Border Protection].

Don't Bring These Items Across the Border

This CBP officer uses a high-tech device to peek inside this van for contraband.
This CBP officer uses a high-tech device to peek inside this van for contraband.
U.S. Customs and Border Protection

Prohibited and Restricted Items are items that you are forbidden to bring into the U.S. Examples include drug paraphernalia (unless you have medical permission for its use), illegal substances (including medications that are not legal in the U.S. or not sold without a doctor's prescription) and counterfeit products.

The list of restricted items is long and extensive. Some of them include:


  • Food products: Bakery goods and certain cheeses are allowed into the U.S. Some imported foods are also subject to requirements of the U.S. Food and Drug Administration (FDA).
  • Fish and wildlife, and products made from them: These are subject to state laws, import and export restrictions, prohibitions, permits or certificates as well as quarantine requirements. For details, contact the U.S. Fish and Wildlife Service (FWS) before you leave if you plan to bring back any wild birds, land or marine mammals, reptiles, fish, shellfish, mollusks or invertebrates or parts of these (such as feathers, bones or fur) or products made from these parts (such as ivory combs or tortoiseshell boxes). FWS must be apprised of products made from endangered species and must issue permits to import them. If the ivory product is made from a warthog or is at least 100 years old, it can be imported as long as this can be documented. The U.S. Fish and Wildlife Service can be reached at 1-800-358-2104. These items are dealt with only at certain customs entry ports, so contact CBP for a list.
  • Plants or plant products: Every seed, cutting and plant must be declared and brought out for inspection no matter how clean or pest-free they may appear. Many require import or export permits, and some are completely forbidden.
  • Drugs and medications: The FDA forbids the importation (either on your person or by mail) of medications, narcotics or devices that it has not approved for use in the United States or is approved for use only with a doctor's prescription. These include nontraditional treatments for cancer, AIDS, arthritis or other medical conditions. These items will be confiscated even if you acquired them through a foreign doctor's prescription.

For the complete restricted list, which ranges from dog and cat fur to Haitian animal hide drums, visit the U. S. Customs and Border Protection Web site.

Also, U.S. law forbids Americans to bring in goods from countries on which travel restrictions are in place, such as Cuba, Iran, Burma (Myanmar) and most of Sudan. The only exception is informational materials (such as books, tapes, recordings or films). If you have been granted government permission to travel to these countries and would like to bring back some things, you'll need a specific license (rarely granted) from the Office of Foreign Assets Control.

It's important to know that most countries have laws to protect their cultural property, such as art, antiquities and artifacts. These laws include export controls and national ownership of cultural property. Even if you bought a piece from a store in that country, you may be asked to prove that you own it before you can bring it back into the United States. While it's important to have export permits and receipts, these provide no guarantee of ownership [source: U.S. Customs and Border Protection].

Although foreign laws may not be enforceable in the U.S., certain U.S. laws, such as the U.S. National Stolen Property Act, may apply. Under this federal law, a person cannot legally own artifacts or art objects that were stolen, no matter how many times the items may have changed hands [source: U.S. Department of Justice].

How Much Duty Will I Be Charged If I Go Over My Personal Exemption?

Once you present your form listing your items to declare, the U.S. Customs agent will place the ones with the highest rate of duty under your exemption. Then, after subtracting your exemptions and the value of any duty-free items, a flat 3 percent rate will be charged on the next $1,000 worth of merchandise (The rate drops to 1.5 percent if coming from insular possessions). Any dollar amount beyond this $1,000 will be charged at the applicable duty rates.

The flat duty rate may only be used for merchandise that is for your own use or for gifts. As with your personal exemption, you may use the flat-rate provision only once every 30 days. Special flat rates of duty apply to items made and acquired in Canada or Mexico.


If you owe duty, you must pay it upon arrival in the U.S. You can pay in cash (no foreign currency), by personal check (drawn on a U.S. bank and made payable to the U.S. Customs and Border Protection), by government check, money order or traveler's check (if it doesn't exceed the duty owed by more than $50). In some locations, you may pay duty with a credit card, but don't count on it -- inquire ahead of time or be prepared to pay by cash or check [source: U.S. Customs and Border Protection].

What If I Unknowingly Violate Customs Laws?

A member of the CBP Beagle Brigade investigates an arriving passenger's luggage looking for proibited agricultural products or meats.
A member of the CBP Beagle Brigade investigates an arriving passenger's luggage looking for proibited agricultural products or meats.
U.S. Customs and Border Protection

Is ignorance a good excuse? The answer is "no." That's why you should play it safe by declaring anything new that you bring back with you.

"The biggest threats are travelers who are smuggling drugs, animals, money or pirated computer programs," Mann says. "An important issue today is that there are people who can potentially export software programs or microprocessors on their outbound travels and import them on their way back in. You can store a lot of information on a disk and carry a lot of chips in a carry-on bag. The Customs Service has made enforcing related laws top priority."


Most travelers are "good, honest people," according to Mann. So, for example, if you bought an envelope of fresh spices on the island of Grenada for your mom and shoved it into your purse and forgot to declare it, you'll probably be given a break (although you'll have to give up your spices due to laws aimed at protecting human health from disease and agricultural products from infestation).

On the other hand, U.S. Customs officials aren't nearly so kindly disposed towards people carrying unauthorized firearms or narcotics, and they will certainly detain you. Nobody enjoys being "frisked," but the U.S. Customs and Border Protection has congressional authority to conduct, as it deems appropriate, bodily searches of anyone entering the United States.

Likewise, nobody wants to be the person who's pulled aside and asked to open his luggage for search. How do customs agents decide who to pull aside? In some European airports, there are literally "traffic" lights in customs lines -- red means stop and get checked, and green means go on through. However, U.S. Customs agents make these decisions based on a sort of "sixth sense" they've developed after years of observing many, many travelers, according to Mann. This "sixth sense" kicks in when a traveler appears to be hiding something or attempts to make a false declaration statement.

Lots More Information

Related Articles


  • Ahern, Jayson. "Project 28: Lessons Learned and the Future of SBInet." (March 14, 2014)
  • Cheng, Lisa. "How to Find the Best Deals at Duty-Free Shops." 2014. (March 15, 2014)
  • Harmonized Tariff Schedule of the United States (2010). "Arms and Ammunition; Parts and Accessories Thereof." (March 14, 2014)
  • Malloy, Michael P. "Tariff Act of 1789." 2004. (March 16, 2014).
  • Mann, Zachary, U.S. Customs and Border Protection, personal interview
  • National Priorities Project. "Federal Revenue: Where Does the Money Come From?" (March 14, 2014)
  • TRAC. "History of the U.S. Customs Service." 2000. (March 16, 2014)
  • U.S. Customs and Border Protection. "Bringing Alcohol from U.S. Insular Possessions into the U.S." (March 18, 2014)
  • U.S. Customs and Border Protection. "CBP Form 4457 Certificate of Registration - Use on Multiple Trips." (March 14, 2014)
  • U.S. Customs and Border Protection. "Currency/Monetary Instruments: Amount That Can Be Brought Into or Leave the U.S." (March 14, 2014)
  • U.S. Customs and Border Protection. "Customs Duty Information." (March 14, 2014)
  • U.S. Customs and Border Protection. "Duty-free Exemption, Gifts." (March 15, 2014),-gifts
  • U.S. Customs and Border Protection. "How Much I Bring Back to the U.S. Duty-Free?" (March 15, 2014)
  • U.S. Customs and Border Protection. "Importing Cuban Cigars." (March 15, 2014)
  • U.S. Customs and Border Protection. "Items Which Can Be Brought Back From the Caribbean Duty-Free." (March 16, 2014)
  • U.S. Customs and Border Protection. "Prohibited and Restricted Items." (March 15, 2014)
  • U.S. Customs and Border Protection. "Requirements for Importing Alcohol for Personal Use." (March 15, 2014)
  • U.S. Customs and Border Protection. "Requirements for Importing New or Antique Firearms/Ammunition." (March 15, 2014)
  • U.S. Customs and Border Protection. "The Mission of CBP Air and Marine." (March 15, 2014)
  • U.S. Customs and Border Protection. "Traveler Bringing Tobacco Products (Cigarettes, Cigars, Bidis) to the U.S. for Personal Use." (march 15, 2014)
  • U.S. Customs and Border Protection. "What Must Be Declared When Entering the U.S." (March 15, 2014)
  • U.S. Department of State. "Bilateral Agreements." (March 15, 2014)
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  • Wallechinsky, David. "U.S. Customs and Border Protection." 2013. (March 15, 2014)