If you are flying from Hawaii to the U.S. mainland for the first time, you may often wonder, "Is this an international flight?"

Hawaii is located in the middle of the Pacific Ocean, which gives a strong psychological feeling of 'overseas travel', but administratively, it is one of the states of the United States (State of Hawaii). So, to conclude, traveling from Hawaii to the U.S. mainland is not an international flight but a 'domestic flight'. There are no passport checks or visa inspections at all. However, some procedures may seem a bit different from other states, which often confuses travelers.

First, Hawaii became the 50th state of the United States in 1959. Therefore, traveling from Hawaii to California, Texas, Washington, New York, etc., is legally just inter-state travel. In other words, going from Hawaii to Los Angeles is similar to taking a domestic flight from Seoul to Busan. However, due to the long distance, most flights take over 5 hours, and the airport structure and security screening process may feel like an international flight. For example, at Honolulu International Airport (HNL), all flights heading to the U.S. mainland are classified as 'Domestic Departures'. There are no immigration checks or customs inspections, and no passport presentation is required.

However, there is a peculiarity due to Hawaii's unique location. When departing from Hawaii to the U.S. mainland, there are restrictions on the export of agricultural products (Agricultural Inspection). This is in accordance with federal regulations (USDA) to protect Hawaii's unique ecosystem by prohibiting the export of certain fruits, plants, seeds, etc., to the mainland. Therefore, when going through bag checks before boarding, you will often see airport staff asking, "Any fruits or plants?" This inspection is entirely different from immigration checks, but many travelers often confuse it with passport checks.

Another confusing aspect is that international and domestic terminals are mixed within the same airport in Hawaii. For example, at Honolulu Airport, there are many international flights coming from countries like Japan, Korea, Australia, and Canada, so there is a separate 'International Arrivals Area' for immigration checks.

However, flights to the mainland depart from the adjacent 'Domestic Terminal'. Therefore, if you misread the signs, you might head towards the international flight direction to look for your passport or prepare your ESTA. However, U.S. citizens, permanent residents, and visa holders do not have any additional immigration procedures when traveling from Hawaii to the mainland.

The only time you need to show your passport is when you are asked for identification (ID) during boarding pass verification. In U.S. domestic flights, you can use your passport for identification, so some travelers conveniently show their passports. However, this is not because a passport is required, but simply because it serves as identification. If you have a U.S. driver's license or REAL ID, that is sufficient.

When leaving Hawaii, if you sit in front of the boarding gate after security screening, you can easily see Japanese, Korean, and American travelers mixed together. Hawaii is such an international area that there are many foreign tourists, making the atmosphere feel like an international airport. However, many of the flights operating there are actually domestic flights within the U.S.

Flights from Honolulu to San Francisco, Los Angeles, Seattle, Las Vegas, etc., are all domestic flights heading to the U.S. mainland, and there are no immigration checkpoints or customs officials.

Conversely, when entering Hawaii from the U.S. mainland, there are also no immigration checks. However, upon arrival in Hawaii, agricultural import regulations are enforced once again. This is a measure to prevent external pests or diseases from entering Hawaii. Therefore, fruits or flowers that were not a problem at mainland airports may be confiscated at Hawaii airports.