Child seats in Japan: the law and renting one with your car

In Japan, a driver may not carry a child under 6 who is not in a child seat. Everyone else in the car must wear a seat belt, in the back seat as well as the front. If you rent a car, reserve the child seats when you book: Nippon Rent-A-Car, Times Car Rental and ORIX Rent-A-Car say they may refuse the rental if you have no seat. A seat costs ¥550–¥1,650, depending on the company and the type.

Is a child seat required by law in Japan?

Yes. A child seat (チャイルドシート) is a seat that holds a child in place in the car. Under the Road Traffic Act (Article 71-3), a driver may not drive with a child under 6 who is not using one. The rule has applied since 1 April 2000.

Rule	What it says
Who	Children under 6 years old
Who is responsible	The driver
Penalty	1 penalty point for the driver; no fine
Children 6 and older	Not required, but recommended until the adult seat belt fits properly

Source: National Police Agency, Child seats protect children; Kanagawa Prefectural Police, Child seat Q&A; Kagawa Prefectural Police, Child seats (checked on 26 October 2026)

Kanagawa Prefectural Police say a child must never be held on your lap. In a crash at 40 km/h, a 10 kg child would weigh about 30 times as much (about 300 kg), and could be thrown out of the car. A cushion, a seat pad or a baby basket does not count as a child seat.

When is a child seat not required?

The law lists some exceptions. Kanagawa Prefectural Police explain them as follows.

Exception	Notes
The car’s seats cannot hold a child seat
There are too many passengers to fit a seat for every child	Use as many child seats as you can
The child is injured or ill, and a seat is not suitable for their health
The child is severely obese or has another body condition that stops the seat being used properly
Someone other than the driver must care for the child (for example feeding or changing nappies) and cannot do it in the seat	Stop the car if you can
The child is riding in a bus or taxi
The car is used for passenger transport under a special permit (Road Transport Act Article 80)
The child must be taken urgently to hospital or a government office

Source: Kanagawa Prefectural Police, Child seat Q&A (checked on 26 October 2026). The exceptions come from the Road Traffic Act Enforcement Order and apply across Japan.

A child under 6 who is big enough to wear the seat belt properly does not need a child seat, but must then wear the belt.

Which type of child seat does my child need?

Child seats come in three main types. Kanagawa Prefectural Police give these guides. The exact sizes depend on the maker, so check the label on the seat.

Type	Age (guide)	Height (guide)	How it is used
Baby seat (ベビーシート)	Newborn to about 1 year	About 40–85 cm	Faces backwards, or lies flat like a bed
Child seat (幼児用)	About 15 months to 4 years	About 76–105 cm	Faces forwards, once the child can hold up their head and sit alone
Junior seat (ジュニアシート)	About 4 to 12 years	100–150 cm (with backrest); 125–150 cm (without)	Raises the child so the adult seat belt fits

Source: Kanagawa Prefectural Police, Child seat Q&A (checked on 26 October 2026)

Approved child seats carry the national approval mark. Kagawa Prefectural Police say the mark looks like “C-◯◯◯”.

Where should the child seat go in the car?

The National Police Agency gives this advice:

1. If the car has a front passenger airbag, fit the child seat in the back seat whenever you can.
2. If you must use the front passenger seat, slide that seat as far back as it goes and face the child seat forwards.
3. Follow the child seat’s instructions, and check that it is held firmly to the car seat. A loose seat does not protect the child.

Source: National Police Agency, Child Seats Save Children (checked on 26 October 2026)

Times Car Rental also says it does not recommend the front passenger seat, and that its child seats cannot be fitted in the middle seat.

Do back-seat passengers have to wear a seat belt?

Yes. The driver must wear a seat belt and make every passenger wear one, in the front and in the back, on all roads. The only exception is a good reason such as illness.

Situation	Penalty for the driver
A back-seat passenger is not wearing a belt on an expressway or motorway	1 penalty point

Source: National Police Agency, Wear a seat belt in every seat; Fasten Your Seat Belt Wherever You Are Seated (checked on 26 October 2026)

The National Police Agency also says that if a passenger is hurt worse because they did not wear a belt, that can be treated as their own fault, and they may not get full compensation. See Japan road rules for the other basic rules.

How do I rent a child seat from a rental company?

Choose the seats as an option when you book online, and say the age and size of each child. The companies below say you must fit the seat yourself. Staff may help, but checking that it is safe is your job.

Company	Seats and fees (tax included)	What the company says
TOYOTA Rent a Car	Baby or child seat ¥1,650 per rental; junior seat ¥1,100 per rental	Tell Toyota at booking if you are travelling with a child under 6. Some options may not be available at some shops
Nippon Rent-A-Car	Baby, child and junior seats ¥1,100 per rental	Reserve in advance or bring your own. It will not rent the car if you have no child seat for a child under 6. Seats are limited in number and you may get a non-ISOFIX seat
Times Car Rental	Infant seat ¥1,100; toddler seat ¥1,100; booster seat ¥550	Rental may be refused if child seats are not reserved or brought. Seats are subject to availability
ORIX Rent-A-Car	Baby seat ¥1,650; infant seat ¥1,650; student (junior) seat ¥1,100, per seat	Reserve when you book. Rental may be refused if no seat is reserved or brought. You cannot rent a child seat without a car

Source: TOYOTA Rent a Car, Options; Nippon Rent-A-Car, Child seats and User guide; Times Car Rental, Options and FAQ; ORIX Rent-A-Car, Options and FAQs (checked on 26 October 2026)

Each company also lists sizes for its own seats. For example, ORIX lists its baby seat for under 10 kg and under 75 cm, its infant seat for 9 kg to under 18 kg, and its student seat for 18 kg to under 32 kg. Toyota lists its booster seat for 15–36 kg and 100–150 cm. Check the company’s page for your child.

If a seat is damaged, soiled or lost through your handling, Nippon, Times and ORIX say they may charge you. See booking a rental car for the booking steps.

How many people fit in the car with child seats?

Fewer than the car’s seat count. Nippon Rent-A-Car gives these limits (children in the seats are counted).

Car	With 1 child seat	With 1 junior seat	With 2 child seats
5-seater	4 people	5 people	4 people
8-seater	7 people	8 people	7 people

Source: Nippon Rent-A-Car, Child seats (checked on 26 October 2026)

Nippon also says child seats cannot be fitted in vans or trucks, and lists different limits for the Toyota SIENTA and other 7-seaters. Times shows the approximate number of seats per car size on its options page. If you are a large family, check before you choose the car class.

Can I bring my own child seat?

Some companies say yes:

Company	What it says
Nippon Rent-A-Car	Reserve a seat or bring your own. It cannot judge whether a seat you bring suits your child
Times Car Rental	You are free to use your own seat. Install it yourself and do the final check
ORIX Rent-A-Car	Your own seat is allowed. Staff may help, but you set it up yourself
TOYOTA Rent a Car	Not stated on its English options page. Ask when you book

Source: Nippon Rent-A-Car, User guide and Child seats; Times Car Rental, FAQ; ORIX Rent-A-Car, FAQs - Reservations in general; TOYOTA Rent a Car, Options (checked on 26 October 2026)

If you bring your own, check that it can be fixed firmly in a Japanese car and follow its instructions.