If you’re often tempted to take home a haul from the airport’s duty-free shops, there’s one thing you need to know before you stuff your carry-on with goodies: You’re not necessarily getting a good deal.

A duty-free store is where you can buy certain goods without the added import or export tax that a country normally tacks on. Typically, the best duty-free deals are on liquor and tobacco products, since those are the most heavily taxed items in normal stores. Duty-free stores also often carry makeup, perfume, designer purses and shoes, electronics, and jewelry, but these items are not always priced better in a duty-free shop than in a regular store, so do your research before you buy. But if you’re in these eight destinations, shop away — the duty-free bargains are worth it.

1. Iceland

Duty Free Iceland, in Keflavík, is one of the best places to shop duty-free. It’s tax-free, open day and night, available to both arriving and departing passengers (regardless of origin or destination), and carries both international products and Icelandic specialties, including Icelandic cosmetics, candies, spirits, and beers. This makes it the ideal spot to purchase items you’ll need on your trip or bring back special souvenirs to enjoy at home. Best of all, the prices here are up to 50 percent off the prices you’ll find in the country once you leave the airport, so it’s worth grabbing a bottle or two of booze after your flight arrives, so you don’t have to pay an exorbitant amount for a drink back at the hotel.

2. South Korea

Photo: Yury Stroykin/Shutterstock

If you’re into designer fashion, Seoul’s Incheon International Airport may be your next preferred destination. That’s because it’s home to the world’s first Louis Vuitton airport store, so you can get your hands on the brand’s luxury goods without paying your country’s added import/export fee. Foreign luxury goods tend to receive a hefty markup, which means the airport duty-free store can be a great place for those in the market to purchase them. In addition, the selection at Incheon is huge; the airport has over 90 duty-free stores, such as Burberry, Chanel, Rolex, and more.

3-5. US Virgin Islands, Guam, and American Samoa

Some call the US Virgin Islands — St. Croix, St. John, and St. Thomas — the best duty-free shopping in the Caribbean. That’s because the duty-free shopping allowance here is $1,600, which is double that of many other places, and you can take home up to six bottles of liquor, as long as one of them is a product of the islands. Fortunately, both Cruzan and Captain Morgan have rum distilleries in the US Virgin Islands.

The same goes for Guam, in the western Pacific Ocean, (a very popular destination with Asian shoppers) and American Samoa, in the South Pacific Ocean. These three countries are considered insular possessions of the United States, which means they’re subject to different tax rules than other countries: As long as you’re there 48 hours or more, your tax-free exemption is $1,600.

6. Cruise ships

If you’ve ever taken a cruise, you may have noticed that, no matter what the cruise line or destination, every cruise ship has a duty-free store or even an entire duty-free shopping center, like on the new Celebrity Edge, with its onboard Cartier, Tiffany & Co., and Bulgari stores. This is for a reason: Duty-free stores on cruise ships tend to be able to offer great deals.

Because cruise ships remain in international waters except when in port, their duty-free shops can be open any time the ship is sailing. Liquor and cigarettes are two popular purchases for cruising duty-free bargain hunters. However, keep in mind that sometimes your home port will charge an import fee, as laws differ from state to state and country to country.

7. Caribbean islands

Other than US territories, the Caribbean region is known as one of the best places for duty-free shopping, due in large part to the Caribbean Basin Initiative (CBI). According to the Office of the United States Trade Representative (USTR), “The CBI is intended to facilitate the development of stable Caribbean Basin economies by providing beneficiary countries with duty-free access to the US market for most goods.”

Here’s what this duty-free access looks like for travelers: According to US Customs and Border Protection, “As a general rule, travelers to Caribbean Basin Initiative (CBI) countries are allowed an $800 duty-free exemption on their return to the US. You may include two liters of alcoholic beverages with this $800 exemption, as long as one of the liters was produced in one of the CBI countries.”

In other words, travelers can purchase more tax-free goods to bring home from the Caribbean than from other countries. Currently, there are 17 CBI countries, including the Bahamas, Barbados, Jamaica, and St. Lucia.

8. London Heathrow Airport

Photo: Heathrow Airport/Facebook

Sometimes, what makes for the best duty-free shopping isn’t necessarily the biggest discounts but the widest selection. In that line of thinking, London Heathrow is one of the best places for duty-free deals. As England’s largest airport, Heathrow has five terminals worth of retail space.

Major international brands are clustered in Terminal 3 (there’s around 40 high-end outlets to peruse), while travelers can find local English goodies tax-free in Terminal 5’s shops — think Cath Kidston, Mulberry, Paul Smith, Harrods, a Harry Potter Shop, as well as your last call for a Boots run — making England a great place for duty-free shopping no matter what kinds of goods you’re after.