Osaifu-Keitai puts Sony's FeliCa chip inside a mobile phone so that holding the handset near a reader completes a payment or an authentication. NTT Docomo began offering it in 2004, and au and SoftBank handsets followed. It carries electronic money such as Suica, PASMO, Rakuten Edy, nanaco and WAON, and it covers transit fares through Mobile Suica. It is not a relic of the feature phone era: as of 2026 it remains a common feature on Android smartphones in Japan.
The distinctive part is that the FeliCa chip itself draws power from the electromagnetic field of the reader. On the feature phones of the past, that is why a payment or a trip through a ticket gate still went through on a flat battery. On current smartphones, whether it works while the handset is off depends on the model and its settings, and on many handsets it does not - so it is safer not to count on tapping through a gate with an empty battery. Communication runs at 212kbps or 424kbps and a tap finishes in roughly 0.1 seconds. The standard was designed for situations such as ticket gates, where each passenger has to be processed in about half a second, and that design goal is what sets it apart from schemes that spread later.
Contactless standards fall broadly into TypeA/B and TypeF (FeliCa), and TypeA/B is what the rest of the world mostly uses. Osaifu-Keitai relies on TypeF, so it differs at the radio level from the way Apple Pay and Google Pay are implemented outside Japan. That said, every iPhone from the Japanese iPhone 7 onward supports FeliCa, which is why Apple Pay can hold Suica and iD. The common misunderstanding is the outdated idea that "Apple Pay does not do FeliCa"; handsets sold for the Japanese market handle both FeliCa and TypeA/B. Older models bought overseas may lack FeliCa, so if you plan to use a transit IC card in Japan, check support before you rely on it.
The step that trips people up most often is changing handsets. Balances and points for electronic money live in a protected area of the device itself, so wiping or cancelling the old handset without running each service's transfer (deposit) procedure can leave the balance unreachable. Another frequent misreading is that moving the SIM card to a new phone carries the balance across; it does not. If the handset is lost, suspending the line is not the same as suspending the electronic money, which often needs its own request, so it helps to know the steps in what to do first when a smartphone is lost before you ever need them.
Osaifu-Keitai has nothing to do with calling as such, yet it greatly widened "what a phone can do" during the feature phone years and holds an important place in Japanese mobile history. The history of telephone hardware looks back on that distinctly Japanese mobile culture.