What can a phone carry instead of a card?

What the phone is actually doing

It is emulating a card, which the card emulation page describes and which needs either a secure element or the operating system routing the exchange to an application, the two arrangements the secure element page and the host card emulation page set out.

What it presents is not the card in your wallet. A payment credential is issued to that device, so a terminal sees something specific to the phone rather than the number printed on the plastic, which the phone payment page covers and which EMVCo specifies.

That single fact runs through the whole section. Nothing here is a copy of anything, which is why a card cannot be duplicated into a phone by holding one against the other, and why everything in a phone has to be issued to it.

Who decides what it presents

Three parties, in this order. The platform decides which application answers a terminal: on Android that is a default service for a category and, in recent versions, a wallet role, with a documented way for a foreground application to take precedence, as the Android card emulation reference sets out.

The issuer decides whether a credential may exist on a device at all, and under what conditions it is provisioned, revoked and reissued.

And the terminal decides what it asks for. A payment terminal, a transit gate, a door and a verifier all start the conversation differently, which is why the same phone behaves differently at each.

What the other side has to trust

A plastic card proves possession and nothing else, which the limits page explains is the reason contactless has ceilings at all. A phone can do better, because it verifies the person before it presents anything.

Where that verification is recognised, the rules change: the limit that compensated for a missing check no longer has to compensate for it. Where it is not recognised, the phone is treated as a card.

Identity is the same question with a different answer. What a document proves, what a verifier keeps, and what a holder chooses to show are decided by specifications rather than by the radio, and this section describes them without claiming any of them for the technology.

When the phone changes or disappears

Nothing in a phone moves to a new phone by copying. Credentials are reissued, keys are reissued, and documents are enrolled again, which is the same statement as above seen from the owner's side.

A lost phone is therefore a revocation problem rather than a copying one, and what can be turned off remotely differs by credential. The stolen phone page covers the payment case, which is the one with the most machinery behind it.

This section describes uses. The mechanism belongs to understanding NFC and the risk to security and privacy, and each guide here points at the page it specialises rather than restating it.