Authentication and authorization methods
There are several methods that developers use to seamlessly and securely authenticate an account and enable authorization. As mentioned above, Plaid’s Auth product instantly authenticates an account by retrieving the associated account and routing numbers when the user connects it to an app or service.
This is done either in Plaid Link, where the user enters the account credentials associated with the account they’re connecting, or through OAuth, in which the user temporarily leaves Link to enter their credentials (or log in biometrically) via the financial institution's website or mobile app instead.
If a user doesn’t want to provide their credentials or other authentication methods are unavailable, they also have the option to authenticate their account via micro-deposits. Plaid sends micro-deposits within seconds via instant payment rails like FedNow and RTP, or with same-day ACH as a fallback option. This provides 100% authentication coverage for all accounts while also giving users the choice to continue without providing a username and password.
