> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mangopay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Card fingerprint

The card fingerprint is a unique identifier attached to each card on the platform, allowing you to spot unusual behavior.

The principle is as follows:

* A card is registered with the Card Registration endpoint
* Once the registration process is complete, the corresponding Card object is created
* This Card object comes with a unique `Fingerprint`.

The same card can be registered several times in Mangopay, and will each time get a different `CardId`. The fingerprint, however, remains unique and this even across platforms.

You can take advantage of the following endpoints to spot unusual behaviors:

<CardGroup col={2}>
  <Card title="Endpoint" href="/api-reference/cards/list-cards-fingerprint#list-cards-for-a-fingerprint">
    List Cards for a Fingerprint
  </Card>

  <Card title="Endpoint" href="/api-reference/transactions/list-transactions-card-fingerprint">
    List Transactions for a Card Fingerprint
  </Card>
</CardGroup>