Station Numbers and Signs in Japan: Reading the Letter-and-Number Codes

See how line letters, station numbers and color circles work on Tokyo trains, so you can navigate even when kanji station names are hard to read.

Published October 20, 2026 at 1:57 PM JST | By Tokyo Paul

Quick answer: Many Japanese stations carry a code made of a line letter or letters plus a two-digit number, such as M for the Tokyo Metro Marunouchi Line. The letter names the line, the number gives the station's position along it, and the circle color matches the line. Counting numbers up or down lets you confirm direction and the number of stops left.

What the letter-and-number code is

A station code has two parts. The first identifies the line and is typically one or two letters, often an abbreviation of the romanized line name. The Tokyo Metro Marunouchi Line, for example, uses M. The second part shows where the station sits on that line and is usually a two-digit number, with the starting station commonly numbered 01 on Tokyo Metro lines.

The code is usually shown inside a colored circle or square, so it can be read at a glance. Tokyo Metro explains that each station number sits in a circle whose color matches its subway line, which makes it easy to match a station on the map with the line you are riding.

For a traveler, the code works as a second name for the station. Where a kanji name is hard to read or a romanized spelling looks unfamiliar, a short code such as a letter and two digits can be copied, compared and found again.

A short history of station numbering

Numbering of this kind has a longer history in Japan than many visitors expect. One encyclopedia entry says the first use was on the Nagasaki Electric Tramway, beginning in May 1984. The idea spread slowly, and Yokohama adopted numbering ahead of the 2002 FIFA World Cup.

In Tokyo, Tokyo Metro and the Toei Subway both introduced numbering on 1 April 2004. The Yurikamome line followed on 27 March 2006, and JR East adopted it for its metropolitan area on 20 August 2016. Many operators across Japan introduced it before the 2020 Summer Olympics, a major event expected to bring many international visitors to the country.

The point of all this was practical. Numbers are easier for people who do not read Japanese, and they do not depend on a visitor's ability to pronounce or recognize a station name. They are now a standard part of the signage that guides riders through large networks.

How to read the code on a platform or map

Start with the line. On the subway map, find the line you want, note its letter and color, and then locate your destination's number. The Tokyo Metro guidance lists three simple uses: find the number for the destination on its line, count the stations between where you are and where you are going, and confirm that the train is heading the right way.

Say you stand at a station numbered 08 and need to reach a station numbered 12 on the same line. Four stations away, in rising order, means you want the train that moves toward higher numbers. If the numbers on the next station sign drop to 07, you are going the wrong way.

Platform signs often show the current station code, the neighboring station codes and the direction or final destination. Compare the numbers on the sign with the numbers on your route plan rather than trying to decode every character on the board.

Transfers, branches and shared symbols

Not every network follows an identical pattern. Operators handle branch lines in different ways. One railway, for example, skips numbers on its branch so the main line and the branch do not overlap. Some railways also share a symbol between related lines. The Seibu Sayama Line, for example, shares the SI symbol with the Seibu Ikebukuro Line.

At interchange stations a single station can have several codes at once, one for each line that stops there. Signs at connecting passages often show the line you are heading to, along with its color, so follow the color and letter you need rather than the station's name alone.

Because Tokyo Metro, Toei and JR East each run their own systems, the same station may be reached through different operators with different codes. If you change operators, check whether the gates, tickets and codes change as well.

Reading signs when kanji is hard

Station names in Japan usually appear in kanji, kana and romanized letters on the same sign, and signage in several languages is common at major stations. That makes the romanized name the quickest check for many travelers. The code adds a second check that does not depend on language.

A good habit is to write down three things before leaving: the line name or letter, the destination code, and the direction of travel by number. Matching these on the platform board is more reliable than matching kanji from memory.

Colors help in the same way. Line colors on maps, signs and floor guides let riders follow a route by color in a crowded interchange. When a sign shows only Japanese, the colored circle can still point the way. Exits are normally labeled too, so check the station map near the gates for the exit that suits your destination.

Counting stops and estimating the ride

Because numbers rise or fall by one at each stop, the gap between two codes on the same line gives a quick sense of distance. A destination numbered ten above your starting point is about ten stops away on a train that calls at every station. This helps when deciding whether to stay seated or prepare to get off.

Express and rapid services may skip stations, so the difference in numbers shows the position of the destination on the line, not always the number of stops the train will make. On lines with several train types, check the destination board or the route planner to see which stations a particular train serves. The numbers still confirm direction and the order of stations.

Practical tips and common questions

Take a photo or screenshot of the route map before entering a big interchange, and look at the number of the next station on each sign to confirm direction. Keep to the side of walkways while checking signs, because commuter flow can be fast at peak times.

Remember that stations on different operators may use different numbering conventions, and that rules and signage change over time. This guide shares general information; rules change, so confirm details with the official agency or provider before you act.

If a code looks unfamiliar, ask station staff or look for an information desk. Staff at large stations can help, and tourist information centers are another place to ask. A little practice on a short ride makes the system feel natural by the second or third trip.

Frequently Asked Questions

What does the letter in a Japanese station code mean?

It identifies the railway line. In Japan the line symbol is typically one or two letters, often drawn from the romanized line name, and the Marunouchi Line uses M. The number after it shows the station's place on that line, so the pair together points to one specific station.

Are station numbers the same on every railway in Tokyo?

No. Tokyo Metro, Toei and JR East each run their own numbering, adopted on different dates. Tokyo Metro and Toei began on 1 April 2004 and JR East on 20 August 2016. A station served by several operators can therefore have more than one code.

Do the colors on the signs mean anything?

Yes. Tokyo Metro states that each station number is circled in a color that matches its subway line. Use the color together with the letter to make sure you are boarding the right line, especially at large interchanges where several lines meet.

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