Japan licence conversion (外免切替) – steps and the knowledge test

Updated 7 October 2026

If you already hold a car licence from another country and live in Japan, you can convert it to a Japanese licence instead of starting from zero. The procedure is called 外免切替 (gaimen kirikae). Since 1 October 2025 the knowledge test in this procedure has become much harder than before. This page sums up the main steps and how to prepare for the knowledge test.

50true/false questions
30minutes
45correct to pass (90%)

The conversion knowledge test since 1 October 2025

The old knowledge check for conversion was short, and many people passed after a few evenings of study. Since 1 October 2025 it has been rebuilt to look much more like the written test for people learning in Japan:

50 true/false statements.
30 minutes to answer.
At least 45 correct (90%) to pass.
No illustration questions (the three-part hazard scenes).

A 90% pass mark leaves room for only 5 mistakes. The test covers traffic lights, signs and road markings, giving way at intersections, speed limits, stopping and parking, railway crossings, pedestrians and cyclists. Many Japanese rules differ from what you may be used to: traffic keeps left, a car turning right gives way to oncoming traffic going straight, and you must stop before every railway crossing unless a signal lets you go. Driving experience abroad is not enough on its own.

Sit a 50-question, 30-minute conversion mock exam in the new format.

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Conversion steps at a glance

Gather documents. Usually: your valid foreign licence; a Japanese translation of it from an accepted body (for example JAF); your passport (and old passports if needed) to prove you stayed in the issuing country for at least 3 months after getting the licence; your residence card; a resident record (住民票); and an ID photo. Each prefecture sets the exact list.
Book and apply at the driving licence centre of the prefecture where you live. Many prefectures require a phone or online booking, and slots can be weeks away.
Document check and a short interview about how you learned and were tested abroad.
Aptitude check, mainly eyesight.
Knowledge test of 50 questions as above.
Driving test on the licence centre course, judged by Japanese safe-driving standards.
Receive your Japanese licence after passing and paying the fees.

Each prefecture runs things its own way: application days, available test languages, extra documents and fees. Always check your prefectural police website or call the licence centre before you go.

Who is exempt from the tests?

Holders of licences from certain countries and regions designated by Japan can be exempt from the knowledge and driving tests. Many other licences, including Vietnamese ones, are not on that list, so their holders take both tests.

How to prepare for the knowledge test

Start with what is different from home: keeping left, giving way when turning right, stopping at railway crossings, stopping fully at the line when you see 止まれ, and giving pedestrians priority at crossings.
Learn Japanese road signs: shapes and colours differ from many countries; the stop sign, for instance, is a red inverted triangle. See Japanese road signs.
Learn the numbers: legal speed limits, no-stopping and no-parking distances, alcohol levels.
Practise timed exams until you score 47/50 or better consistently.
Keep up with new rules: for example, from 1 September 2026 the legal limit on ordinary roads with no centre line is 30 km/h. See Japan traffic law updates.

Practise for conversion with ViMai Menkyo

ViMai Menkyo has 20 mock exams dedicated to the conversion knowledge test, each with 50 true/false questions in 30 minutes, a pass mark of 45 and no illustration questions, matching the new format. Exams 1 to 5 are free. Every question has an English explanation that highlights where Japanese rules differ from driving habits elsewhere.

Frequently asked questions

How many questions are on the licence conversion knowledge test?

Since 1 October 2025 the conversion knowledge test has 50 true/false questions in 30 minutes, and you need at least 45 correct (90%). There are no illustration questions.

Are some countries exempt from the tests?

Yes. Holders of licences from certain countries and regions designated by Japan can be exempt from the knowledge and driving tests. Licences from many other countries, including Vietnam, require both tests.

Is the procedure the same in every prefecture?

The overall framework is the same, but booking, application days, test languages and the exact document list can differ by prefecture. Check your prefectural police website before you go.