In this order
Start with medication, because it is the only step measured in weeks
Japan restricts actives that are ordinary elsewhere. Above certain quantities you need Import Confirmation, received before you leave home and shown at customs. No other step has a lead time like it, and nothing can be done at the border if you arrive without it. Korea publishes its own prohibited list separately, so a trip to both needs both checked.
Do both countries' online entry admin, and do not assume one covers the other
Japan's Visit Japan Web handles immigration and customs declarations in advance. Korea's K-ETA is a separate authorisation with its own eligibility and its own age exemptions. That is two systems, two accounts and two checks against your passport.
Check the Korean authorisation against your own passport and age
K-ETA eligibility is set nationality by nationality, and an age exemption at each end of the range removes the application entirely. Whether it applies depends on your passport and your birthday, not your itinerary. Settle it before you pay for anything.
Read the activities exclusion before you buy insurance, not after
Winter changes this step. Skiing, snowboarding and anything off a marked piste are the classic carve-outs, so the activities exclusion decides a winter claim. Evacuation cover and pre-existing-condition wording decide claims in any season. A policy bought on price alone can exclude the reason you went.
Install the eSIM before you fly, and check your devices are legal in Japan
This step bundles two things. Data is cheaper and easier bought at home than at an airport counter, and one eSIM can carry both countries. Separately, Japan's radio law governs which wireless devices may be used in the country, which catches a few travellers with equipment bought elsewhere. Check yours before packing.
Decide the transit lounge on the length of the stop
A winter routing through a northern Asian hub often has a long connection. Decide on the hours to fill, not on tiredness. Where a lounge is worth buying, buying in advance is usually cheaper than paying at the door.
Book rail after the entry admin, because passes are dated
Passes and reserved seats are bought against fixed dates, so book them after the entry admin is settled and before the discretionary spending. A pass bought before a K-ETA determination rests on an assumption. Price it rather than assume it: a regional pass beats the point-to-point fares it replaces on some itineraries and not others, depending on how much of the route you cover. For the national Japan Rail Pass, where you buy matters too: from 1 October 2026 overseas agents charge JPY 53,000 for 7 days while JR's own online site holds JPY 50,000.
Leave the tax-free shopping until you understand what qualifies
Japan operates tax-free shopping for visitors on goods taken out of the country, and Korea's traveller refund works the same way, on goods presented unopened at departure. Both cover things you carry home, not the trip itself, which catches people who expect money back on a hotel.
Winter adds lead times to a trip to Japan or Korea. The flights behave as in any season. The paperwork does not, and one insurance clause only matters with snow on the ground.
The steps below run in order of how long each takes. The first can take weeks and has no remedy at the border. The last can wait until the week before. Each step points to a guide with the sourced rule. The sequence is our judgement, so this page cites no single official source of its own.
Start with medication
Everything else on this list can be done in an evening. Medication cannot.
Japan restricts actives that are unremarkable elsewhere. Above its quantity thresholds you need Import Confirmation, received before you leave home and shown to the officer at customs. No airport counter fixes this, and without it your prescription cannot legally come in with you. Korea publishes its own prohibited list, and neither list is a subset of the other, so read both.
If you take anything daily, start today.
What winter changes
- Insurance. The activities exclusion decides a winter claim, and most policies bury it. Skiing on a marked piste, skiing off it and snowboarding are often treated as three different risks.
- Entry admin. Visit Japan Web and K-ETA work the same in February as in July, and both are done online from home.
- Tax-free shopping. Both countries cover goods carried out of the country and presented at departure. Neither covers the trip, and a hotel night is not a good you can present. This disappoints a predictable number of visitors every winter.
What is worth buying, and when
- eSIM, before you fly. One plan carries both countries, and an airport counter is the expensive way to solve the same problem. Saily fits into the same evening as the entry admin.
- Insurance, read for its exclusions. In winter that means the activities clause, so what a policy excludes matters more than what it costs. A policy that excludes off-piste is not cheap if off-piste is why you went.
- Rail, priced rather than assumed. A regional pass beats the fares it replaces on some routes and not others. Put the actual itinerary through Trip.com’s rail search before buying a pass on its reputation.
- Lounge, only where the connection earns it. If you are buying data anyway, Jetpac sells lounge access alongside the allowance, so on a long northern connection the two purchases can be one.
What this page does not sell
- Medication. Nothing legitimately sells compliance with Japan’s Import Confirmation, so the step that can end a trip before it starts has no product attached. Step 1 links a guide and nothing else.
- Japan’s radio law. Step 5 pairs the connectivity purchase with a check on whether your wireless devices may be used in Japan. The link covers the first half only, because no programme sells the second.
Correction
10 September 2026. Step 7 originally said that no programme on this site sells rail, so there was nothing honest to link. That was wrong on the day it was published. Trip.com sells Asian rail, it was already approved and tracked, and our guide to booking Chinese trains had carried a Trip.com rail link since 30 August. The claim has been removed, and the step now carries the link it should have had.
Saily carries Japan and Korea on one plan Our full write-up. (affiliate link)
SafetyWing publishes the activities exclusions in full (affiliate link)
Jetpac bundles lounge access with the data allowance (affiliate link)
Trip.com sells Japanese and Korean rail with an English interface (affiliate link)